Enmity management is still a mechanic in the current game, it's just one that can generally be solved with minimal hassle. So the core question is would the game be improved if there was more hassle involved to managing this.

I can see it going both ways. I can see it being something that gives players something interesting to actually do and manage instead of just mindlessly doing a rotation, but I can also see it being something that creates conflict between players of different skill levels.

For example, if a skilled DPS can pull more enmity than an unskilled tank, and thus create a blame game of whether the DPS should do less damage or the tank should git good, I don't want this system. If players keep getting hit by mechanics, resulting in the healer needing to heal more, and thus the tank can't keep aggro, that also seems like a negative situation where I can envision many parties devolving into finger-pointing. There's just so much potential for this to become something that creates divides between players with different skill levels and different philosophies.

So I would only want more enmity management if it were designed in such a way that it prevents such conflicts.