Actually, it probably did the show a big favour - I find Majel Barrett and Jimmy Doohan's voices to be a bit overused as it is - it would have been a lot worse had they attempted to do Uhura and Sulu as well, as was planned.
Nichols did a lot more than just Uhura. Also Takei had a hilariously awful turn as a cloud thingamajig in Megas Tu.
If they ever go back and redo TAS in CGI form, a big component has got to be redoing a lot of the voice work.