Could also be that they intend to go the other way around, making more streamlined class kits so they can further focus in mechanics.
I mean, when people speak about skill expression, which current encounters permit it anyway? Current endgame content boils down to syncing up your clocks and dancing the same dance else face a whipe. I'm not saying everything should go the way SMN did, but I'd take those streamlined classes if it means encouraging better flowing instances, since it doesn't seems they'll back down from 2 minute meta.