The studio can brand the word "Starship" like phasers and tricorders and warp speed all they like and trademarking it keeps it secure to what belongs to them. I won't be turned to believe what was posted on the bridge of TOS Enterprise to be a mistake because the plaque could've been changed by the art dept at anytime during its run. That kind of branding wasn't necessary for the time, the survival of the series was. I wish a progression of the name was done than forcefully titling TOS Enterprise a Constitution Class retroactively. As we know any advancement in technology machines and tech get smaller and simplified.
By the time of TMP, I wouldn't give much credence for advancement when it came to technology, in TOS the engine room didn't require hazmat, radiation suits or have warp malfunctions producing wormholes, and the functions like defense was separated in it's own sections, and medical tricorders can not even identify the Klingon anatomy (TUC)*. TOS was far more advanced in simplifying ship operations which is what space explorers want for extended missions in space, but by the time of TMP everything appeared more complicated, bigger and clunky than advanced. For me, those over complications of functions gave me the impression after TOS run between TMP there was some sort of galactic technological collapse.
*Yes, I am aware there were malfunctions of the transporters in TOS but was resolved quite efficiently and practical.