The proposal to bump major for all providers with every core minor version seems like a reasonable solution to me, and it sounds like there may be consensus on that? Though eventially the version numbers may get pretty large :)
This discussion came to my attiontion from engagement with the vault secrets enhancement <https://github.com/apache/airflow/pull/15013/files>. Looking at this as a test case for this question, to implement this change while maintaining compatibility with 2.0.0 would require an unacceptable amount of code duplication and mess. And it's a relatively simple change (so we can imagine it being much worse in other instances).
