Ah, in that way, yes. However, most people right now just run in pure berserker setups, so at least this gives SOME chance that one of them will go "Uh guys, gimme a moment, going to use this slick build for the next fight, it's totally awesome" instead of trying to overpower everything with the mighty power of "zerg or die". You still need a good enough knowledge of knowing what you're going to retrait in, in order to take advantage of that - so there's theoretical preparation, rather than practical kind, perhaps.
I dunno, I personally like that change. There's been plenty of times where I was like "Damn, having a slight reshuffle in my skills on this boss would've been amazing, but fuck if I'm gonna do it because it drops my efficiency for the rest of the run, and fuck if I'm going to make my group wait to do this reshuffling and fuck I'll have to reshuffle back after that AGAIN" and it's rather nice that I'll actually be able to try out my ideas in practice (and probably see them miserably fail). Yeah, on the greater scale, it's a general design flaw (why design ONE boss that'll completely fall out of the pattern to make a specific build shine just on THAT particular boss, for example?), but at least this way they can kind of alleviate it a bit.