I never got why Eviolite would matter anywayY'all say Eviolite is blocking further evolutions, but we could still have branch-evolutions like Slowking, Gallade and Froslass without breaking the Eviolite rule.
If the "issue" is why it didn't work before but does now they've already done more obvious retcons any time they change typings of Pokemon or moves. Or changed how abilities work.
If the issue is making older unevolved pokemon stronger they can change how it functions by lowering the boost if absolutely nothing else. Or just not care about it in the first place, they sure didn't seem to when they added the item to begin with.
I've seen both of those floated around for why Eviolite would prevent items and it seems almost comically limiting to see a single weird item put a stop to an entire genre of pokemon ideas.