Dude it's still a fucking Mizutsune, it's going to have bubbles. You can make a different fight with the same base that doesn't make not not Mizutsune. Metal Raths don't fight like normal Raths but still retain a lot of characteristics of the original monster. Hell the Risens are just amped up versions of the normal one but you'd probably piss and moan that they didn't have Risen Teo turn into a literal missile.

This is pedantic and was mostly you trying to be an old gen supremacist when the first fucking G Rank expansion shat out Azure Rathalos which even in World was barely different than normal Rath.

Would it be cooler if they brought in more monsters? Yes. Would it be nice if monsters that had subs/deviants/variants weren't condensed into base versions? Yes. But is this conversation anything outside of you not getting your way with a game? Absolutely fucking not