Here are the verbatim release notes as of Nov 4: for each item, need to evaluate whether some doc update is required.
Ticked means: either not necessary, or doc updated.

10.1.0-rc.4

🚀 New Feature

• Support format check with rescript format -check. Check formatting rescript#5760

🐛 Bug Fix

• Fix issue where the last line of rescript format --help usage was being swallowed Check formatting rescript#5760
• Specialize the printing of the rhs of a record field assignment for optional values {x: ? e} Parentheses when assigning optional value to optional field syntax#714

10.1.0-rc.3

🚀 New Feature

• Support the use of spread anywhere in list creation (e.g. `list{...x, 1, ...y, ...z}). Spread anywhere feature syntax#692 Docs: Update docs for list spread. #598

• Add support for the argument of @react.component to set a props type from the outside. JSX v4 shared props syntax#699

🐛 Bug Fix

• Fix issue where the JSX key type is not an optional string Fix react comp key type syntax#693
• Prevent inlining of async functions Immediately invoked async functions lead to non-working code  rescript#5754
• Fix build error for JSX fragment without children Fix fragment optional children syntax#704
• Fix issue where async as an id cannot be used with application and labelled arguments [10.1] Redefined async functions don't support named arguments syntax#707
• Fix 5557: the exhaustive checking for char is incorrect during the unicode migration Fix char pattern matching in unicode rescript#5749
• Fix 5753: the comment for unicode char is inaccurate Change char payload syntax#709
• Treat await as almost-unary operator weaker than pipe so await foo->bar means await (foo->bar) Treat await as an almost-unary operator. syntax#711

💅 Polish

• Change payload of Pconst_char from char to int Change char payload syntax#709

10.1.0-rc.2

🐛 Bug Fix

• Fix issue with changes not being applied with React Native's Metro bundler for files with warnings Fix .bs.js timestamp being reset to 1970-01-01 when there are warnings rescript#5738
• Fix emitting unary minus for floats in case of negative constants Fix emitting unary minus for floats in case of negative constants. rescript#5737
• Fix issue where a spread ...x in non-last position would not be reported as syntax error Add spread element check when the last element is a spread.  syntax#673
• Fix issue where the formatter would delete async in a function with labelled arguments.
• Fix several printing issues with async including an infinite loop Fix several printing issues with async including an infinite loop. syntax#680
• Fix issue where certain JSX expressions would be formatted differenctly in compiler 10.1.0-rc.1 Unnecessary format changes in JSX between 10.0.1 and 10.1.0-rc.1 syntax#675
• Fix issue where printing nested pipe discards await await lost on reformat syntax#687

10.1.0-rc.1

💥 Breaking Change

• Deprecate DOM element attributes in JsxDOM.domProps: begin_, end_, to_
  • Use begin, end, to instead.
• Emit an error when a @string or @int attribute is used in a V4 component JSX v4 and @string / @int rescript#5724

🚀 New Feature

• Add extra variants for output filename suffixes in bsconfig.json: .bs.mjs and .bs.cjs are allowed Add extra variants for suffixes in bsconfig.json rescript#5631
• Safe promises: t-first Js.Promise2 bindings, and remove warning for nested promises Safe promises rescript#5709

🐛 Bug Fix

• Fix issue where uncurried async functions were emitted without async Fix issue where uncurried async functions were emitted without async rescript#5718
• Fix location issue in error messages with JSX V4 where the multiple props types are defined Better error msg and loc for multiple props type declaration syntax#655
• Fix location issue in make function in JSX V4 that breaks dead code elimination Fix location issue in make function in JSX V4 that breaks dead code e… syntax#660
• Fix parsing (hence pretty printing) of expressions with underscore _ and comments.
• Fix printing of comments inside JSX tag fix: Avoid tail comments inside tag from being eaten syntax#664
• Fix issue where formatter erases tail comments inside JSX tag Formatter erasing comments syntax#663
• Fix issue where the JSX prop has type annotation of the first class module Fix JSX v4 for first class module syntax#666
• Fix issue where an empty record literal {} expected to have a non-record type would type check Fix issue where an empty record literal {} expected to have a non-record type would type check rescript#5729

👓 Spec Compliance

• Functions with consecutive dots now print as multiple arrow functions like in JavaScript.

💅 Polish

• Add loading, aria-* DOM element attributes in JsxDOM.domProps: ariaCurrent, ariaInvalid, ariaAutocomplete, etc.
• Change the internal representation of props for the lowercase components to record. JSX v4 record-based representation for lowercase syntax#665

10.1.0-alpha.2

🚀 New Feature

• Fix pretty printer where it would print doc comments on the same line as other attributes Fix printing doc comments before attributes syntax#642
• Propagte "jsx" configuration to dependencies Propagate jsx config to dependencies, and add config "preserve-dependencies". rescript#5661
• Add support for empty record literal {} for records where all fields are optional Support {} for empty record literals and types. rescript#5658
• Add support for empty record type (e.g. type empty = {}) Support {} for empty record literals and types. rescript#5658

🐛 Bug Fix

• Fix issue in formatting JSX spread props Spread props syntax#644
• Fix location issue in error messages with JSX V4 where the body of the component is an application Add loc for returned component body syntax#633
• Fix printing of type declarations in error message where they would be considered recursive by default
• Fix issue where the printer would omit attributes for -> and |> Pipe reformat eats annotation syntax#629
• Fix printing of optional fields in records Optional record fields rendered incorrectly in type errors rescript#5654

💅 Polish

• Improvements and fixes for JSX V4. See guide https://github.com/rescript-lang/syntax/blob/master/cli/JSXV4.md
• Mention all missing fields in error message for records, not just one Print all missing labels in error message for records, not just one. rescript#5657

10.1.0-alpha.1

💥 Breaking Change

• Vendor genType, which does not need to be installed separately anymore. Only TypeScript back-end supported. Update genType docs after the move inside the compiler. #597
• Pipe -> does not support a code block on the right-hand side e.g. x->{ open A; get("test") }

🚀 New Feature

• Experimental support for for async/await Async await support rescript#5537 DOC:Add documentation for async/await. #590

• Make promise a built-in type Make promise a built-in type. rescript#5650

• JSX V4. Update React page #593

• Add placeholder types for ES6 collections: Set, Map, WeakSet, and WeakMap Add placeholder types for ES6 collections rescript#5630

🐛 Bug Fix

• Fix issue with arrays and creation of recursive values Fix issue with arrays and creation of recursive values. rescript#5640
• Fix issue where characters such as newlines would be escaped in a template string expression Incorrect escaping with multiline strings rescript#5638
• Fix issue where pipe -> processing eats up attributes Fix issue where pipe "->" processing eats up attributes. rescript#5581
• Fix issue where cancelling rescript build would leave the .bsb.lock file behind and block future builds

💅 Polish

• Print patterns in warnings using rescript printer POC: print patterns in warnings using rescript printer rescript#5492