So, lots of examples, but not much on your question about terminology. In looking around a bit, I couldn't find a single specific term for a malapropism that "sticks," but you could fairly describe it as a form semantic drift driven by catachresis, thought the latter seems more common in literary criticism or philosophy than in linguistics.
Even then, I can't quite find a single Linguistics term for this phenomenon, where it becomes a thing of its own or even replaces the original. 'Eggcorn' and 'Malaphor' seem to be pretty decent casual terms.
Almost thought you'd done one yourself there with this "even then"! But I was thinking of even still (from even so). Which BTW is probably in my top 3 most hated malaphors or catachreses or whatever they are.