I am also interested, if there is some kind of “official statement” from Atlassian stating that if “X” happens, then a connect app is no longer considered “connect”, but rather “this is forge app from now on”.
Since on the platform there will be warning messages shown for customers about phasing out of the connect platform - so how it can be made sure that for an app that was migrated (mentioned blocks of code removed) those warning won’t show up.
It was only May 26th that they first informed partners in a buried thread reply that they would be plastering warning messages on apps 3-6 months before EOS. And that was only first discovered by partners because they pushed it to prod without any warning.
24 July: warning messages on apps are displayed to admins in prod
30 July: adoption-status deployed publicly for @atlassian/connect-to-forge
If you’re still actively developing the tooling and documentation for Forge migrations, perhaps that should indicate that it’s far too early to be plastering warning messages on Connect apps.