Life is messy. I like
"Vulcanian" as an early form, no longer used. Language changes over time, so I think such terms should be acknowledged, and even used in appropriate context.
I also dislike retcon vocabulary, such as "warp core" in relation to pre-TNG-era ships. It makes a lot of sense, gets the idea across easily and succinctly, but should never be used in-universe
much before 2364.
It's all a matter of what makes sense in what context. Fans discussing the warp core of Archer's Loknarprise? Sure! Scotty discussing the warp core of the Antares from Charley X? Hell no, that's as anachronistic as a 1940's PI saying "LOL, doll! LMAO while yer on yer way to the pen!". Harry Mudd calling Spock a Vulcanian, yes. The Outrageous Okona saying it, no.