This all muddies the waters quite nicely.
Starship/Constitution/Enterprise Class - very close to the source. Anyone still not think that a couple of these things should be forceably decanonized like "Vulcanians"? Personally, I think "starship" should not ever be considered a class-name again, but rather a generic ship type, like "xxxx-class starship" is fine. We've heard this combination of words in relation to space-faring vessels for a much longer duration than "starship class" (a phrase which has never been voiced on-screen in dialog). Think about it - is anyone ever REALLY going to call the Enterprise a "Starship-Class Starship
"? That's like calling today's Enterprise a "Carrier-Class Carrier"! Are we going to say that one piece of set dressing (original bridge plaque w/ "Starship Class") that was never meant to be seen that clearly is any more or less authoritative than another piece of set dressing (technical journal w/ "Constitution Class")? It's time to collectively kill "Starship Class" once and for all. It is a meaningless pairing of words. At least "Constitution Class" makes sense and, even though never spoken on-screen in TOS, it was
spoken on screen (satisfying most people's definition of the word "canon") in relation to that specific type of vessel in TNG and beyond. Any confusion or debate about what class the TOS Enterprise belonged to should have evaporated with that.
I kind of miss the old days of debating whether or not the refit was called a Connie or its own new "Enterprise Class" (based on the TWOK bridge simulator signage). I'm an "Enterprise-class" guy m'self.