>>14324481I'd prefer better type match ups first. Making water weak to poison and shit.
Otherwise there's not much that they could implement. Or at least not much they could retcon old pokemon into.
Sound type sounds nice but there's nothing previously outside of a handful of pokemon that would use it.
Retconning old pokemon may not have been a big deal in gen 2 but now that there's 700+ pokemon any new type would be severely under represented if they didn't have some old pokes to throw in there too.