The fact that this bill got as far as it did is horrifying, and in an ideal world, every Republican who was up for re-election in 2022 (i.e. "safe" from primarying for a time) would have been in revolt. But I'll take 3 Republicans in revolt over none, so sure, credit where credit is due.
Re McCain, I think that the problem is that people interpret 'maverick' in the wrong way. There's 'maverick' meaning "moderate", so something like Collins or Manchin, and there's 'maverick' meaning "has actual principles they put ahead of advancing the party." McCain is quite conservative but has his own drum he marches to. So expecting him to be a cuddly Democrat in disguise is going to get you bit. What McCain is useful for is that there's a lot of "process" / "values" principles that have unfortunately become politicized that used to be, or at least *should* be, non-partisan. "Is torture bad", "should unlimited money slosh around in politics", "are immigrants real people", etc. In that, he unfortunately does deserve praise. (Alternatively, "most other Republicans deserve scorn", if you must.) Who knows why he voted the way he did, but the best guess seems it was process related, also possibly brush with death related. Who knows. Also, on the process note, fuck all the Republicans who whined about the way Obamacare was passed (in a chamber that had 59 Democrats) but didn't see any issues with how BCRA was attempted to be passed.
Dunie, just focusing specifically on the McCain attention vs. Collins & Murkowski... well, McCain was the surprising vote is the thing. In the alternate universe where Portman & Heller were steadfast Republican opponents from start to finish, and Jodi Ernst or Deb Fischer cast the surprising vote to push the bill off the cliff, then it'd be Ernst getting all the attention. It's the marginal vote that matters.
Re NotMiki on the trans-in-the-military issue, my budgetary foo is weak, but couldn't Trump have simply announced that the military will no longer pay for any costs related to gender reassignment surgery if that was his angle, not from Budgetary authority (which rests with Congress), but from his powers as Commander in Chief? I'd certainly think it'd work in reverse, i.e. Obama ordering the military to let it happen without need for Congressional intervention. (Granted, not sure it matters whether it was the paint chips making him not notice this obvious option, or if he genuinely did want to throw a bone to the religious right by doin' some ol' fashioned gay bashing. My money is slightly on the gay bashing, FWIW.)