I don't think so. They certainly had different nationalities and races represented in their crew line-up. But that's to be expected of an international space-team. Certainly nothing new.
Looking at it from today's perspective, it's to be expected, but that wasn't necessarily the case in the 1960s, when there were still race riots and blatant discrimination in many parts of the United States. You won't find many SF shows or movies from that era that portrayed racially mixed space crews. Discovery
's crew in 2001
was all-white as far as I could tell.
But was TOS revolutionary? No. Progressive, yes, but not revolutionary. If anything, Roddenberry needed to be prodded by NBC to be more inclusive, after giving them an all-white cast in "The Cage." Demographic studies in the mid-'60s had shown that minorities were active consumers and television viewers, so networks and advertisers realized they could make more money if their shows were more inclusive. So the networks pushed their producers to cast more diversely, which was seen not only in ST, but in shows like Mission: Impossible
(whose Barney Collier was one of the most positive and empowering portrayals of a black character in the era, and far more central to the cast than Uhura ever was) and Land of the Giants
I'm particularly at odds with the claim that the first interracial kiss is often credited to Star Trek. The problem with that is that it's not true. I don't know if the Star Trek production team as a whole is taking credit for that, but I don't see a rightful denial.
Well, that's where we get into America's particular preoccupations and perceptions of what "race" means. Because of the way slavery and its legacy shaped our history, Americans have long had a tendency to perceive race in dualistic terms -- "black and white" in more ways than one. "Interracial" tended to be seen as synonymous with "between black and white," with other racial categories glossed over. That's because, in the '60s, other interethnic romantic pairings weren't as controversial or shocking as black-white unions. You could have Lucille Ball and Desi Arnaz as a couple in the '50s without much controversy, not to mention Shatner kissing the French-Vietnamese France Nuyen in "Elaan of Troyius" (which was filmed before "Plato's Stepchildren" but aired later). But a white person kissing a black person was a drastically different matter. After all, it had been only a year and a half earlier that the Supreme Court had struck down all anti-miscegenation laws which barred marriage between blacks and whites in many states of the union. And several states kept those laws on their books even though they could no longer legally enforce them.
So no, maybe the usage of the word "interracial" there is not technically accurate, but there's a lot more at issue here than vocabulary. A black woman and a white man kissing on TV in front of millions of viewers was a really, really big deal in 1968, because there was still a lot of blatant, hateful racism in the country. So yes, even with the vocabulary quibbles, it was a major landmark. It was the first black-white kiss between adults on American television, and that was a really big deal.
Which brings up another question, if TOS was a groundbreaking show, why did the groundbreaking stop with TOS? I admit to not having watched the other series (save a few Next Generation episodes), but I've never heard of anything groundbreaking as far as any of the following series goes. Did being revolutionary become less important after TOS?
Well, part of it is that society itself had come so far in following TOS's lead since then, so it was more incremental from there -- including a disabled lead character like Geordi, or a black lead like Sisko, or a female lead like Janeway. And there were some moments of daring. The same-sex kiss between Terry Farrell and Susanna Thompson in DS9's "Rejoined" sparked a lot
of controversy at the time, almost rivalling the Kirk-Uhura kiss. It wasn't the first same-sex kiss on commercial TV, but it was within the first half-dozen or so and one of the most overt up to that time. There was at least one affiliate in the South that refused to show the episode, and plenty of people wrote or called in with complaints and protests.
Still, another part of it was that the later shows were so much more successful than TOS had been. The franchise was Paramount's top moneymaker for many years, and when there's that much money invested in something, people get reluctant to take chances with it. Not to mention that by that point, ST had come to be seen as the SFTV establishment, the stalwart institution, rather than the risk-taking, envelope-pushing upstart that TOS had been.