Apple's decision to make the change in 12.3 was bizarre, not communicated in advance, and caught everyone off guard.
Semantic Versioning, which everyone thought Apple was following, is not random. You change the first number when you make backwards incompatible changes. You change the second number when you add new features. You change the third number when the APIs are unchanged but you're making bug/security fixes.
Apple changed the second number but made backwards incompatible changes - features which worked fine for the past decade were suddenly broken by Apple.
Apple did communicate that they would make the change at some point - everyone assumed it would be in a major update. Historically, Apple does their major updates in the Fall, and they give a heads up on all their major Fall updates during WWDC, giving 3 months of time for companies to update their programs accordingly to stop using the old APIs.
Honestly, this is just another sign that Apple doesn't understand software and that we should switch to another OS.