This has been the case since android 6. It just didn’t show you that message and would simply refuse to update non-play store apps.

I have an open issue to try to get a developer strike going for the keepandroidopen project, but unfortunately it hasn’t gotten any attention from the maintainers.

I make like 4 android apps and would be more than happy to remove them from the play store by the deadline, especially if more devs were involved.

Were you previously able to update apps you didn’t install from google play through google play lol?

a lot of them will straight up refuse to open without the play store at all. dunno if there’s a workaround yet.

What I meant by this image is the fact all your apps, which you have from Play Store alternatives won’t be able to be updated in the future most probably. I have no idea if ADB will help when Google might require credentials.