Regression as Institutional Memory. A test suite is the codified set of claims an organisation has committed to believing about itself. Every regression failure is either a discovery (the world changed) or an amnesia event (we forgot why we believed this). The epistemology angle here is rich — Wittgenstein's On Certainty[1] is a good touchstone. This would also give you a stronger argument than you've yet made for why deleting tests is sometimes the right move.

[1] https://plato.stanford.edu/entries/wittgenstein/#OnCe