Failing tests used as a "start here" are to-dos in this instance and are indistinguishable from legitimate currently-implemented feature tests if you've been away long enough.
I don't think it's good to assume it's okay to delete failing tests when returning to a project with new goals or when a bug needs fixing. For me, it's important to return to a project, run tests and have them all come back green. Then if I break something, I know it broke and isn't just an artifact from my pseudo to-dos.
Along those lines... I always try to run tests, check code coverage (including via mutation testing), and commit changes before calling it a day.