In preparation of the next release, I've looked at the migration guide which was mostly referring to 2.0 as something that would happen in the future, but it has been released 2 years ago now. Accordingly:

• I now call it 2.x instead of v2.0 to clarify that it's real.
• I updated the important changes to be accurate as of the 2.4.0 release, including the fact that 2.x supports 3.9+
• I reordered the "Common upgrading issues" section to include the actual issues first, then application migration guidance, and package maintenance last. (At this point, libraries have moved on, but applications.)
• I clarified that 1.26.x does not currently receive security fixes.