That’s fine and I have no objective argument against it. But I don’t see much reason to need two different names for tests that do the same thing merely based on how they were introduced. Sometimes I add a regression test because I fixed a bug, and sometimes I add a regression test because I just implemented a feature that I don’t want my future self to ruin: six months from now they will co-exist in the same suite and serve the same function.
One reason to call bug fix tests for “regression tests” (and only those kinds of tests) is that someone might regress the code base through a merge conflict (maybe they effectively undo a commit?). So that’s one argument I suppose.
"Regression testing" can also refer to a process: When the QA team says they're doing regression testing, it means they're testing that existing functionality hasn't regressed (as opposed to testing a new feature).
I'm not particularly wedded to any of these terms, I'm just pointing out that "regression testing" has an established meaning, and it isn't snapshot testing (outside of certain industries, at least). I do find it amusing that one implementation of snapshot testing (https://pypi.org/project/pytest-regtest/) links to https://en.wikipedia.org/wiki/Regression_testing but that article doesn't describe snapshot testing at all! Maybe the article changed? Oh well, language changes too. ¯\_(ツ)_/¯
One reason to call bug fix tests for “regression tests” (and only those kinds of tests) is that someone might regress the code base through a merge conflict (maybe they effectively undo a commit?). So that’s one argument I suppose.