I must say that, for example in ToMM to perform well, DPS is much more 'sweaty', too keep CA, keep time on target, and so on.. as compared to healers.

From personal experience, I've been playing healer when I wanted relaxed run. While I don't want that to be an ok healer a person needs the same actions per minute as a professional SC2 player, but to some extent healing became predictive and boring.

So IMO, this change further increases this problem. Short timed mitigation or buffs/debuffs can alleviate this to give healers that want to do more, something useful to do. Not like old, but knowing to buff a TR before shox, or CW when you see their daily, can be a nice addon (I do not mean targeted buffs, those do not work in NW, only the timing aspect).