I love the idea of class-based tier sets aesthetically. I really don't like armor class based sets; I didn't in Tier 9 and I don't now. There are a lot of things about Blizzard to be critical about, but their art team was never one of them. Now I feel like they've taken resources from a place that was consistently putting out good work (even tier sets that weren't my taste still usually had obvious effort put into them) and the result is aggressively mediocrity in a place they've always excelled.
As far as set bonuses, my feelings are less positive. They were nice when they were an interesting bonus that changed gameplay in a compelling way once you had collected the full set. However, on the opposite end they could be very frustrating if you had bad luck collecting sets as the bonuses were almost always a significant impact on DPS. It was also dumb wearing old tier sets in new raids just because the bonuses were too good even if the pieces themselves no longer were to be able to justify replacing them. On the other corner, you had those bonuses that were dumb and bland or worthless and specs that didn't give any fucks about their tier sets at all, which wasn't fun either.
In order for me to be in favour of tier bonuses returning, it would have to be something like:(a) easier to get and more flexible for slots. Something like getting the bonuses with four slots filled but the set containing five or six pieces so you could choose between offset pieces and earn your bonus more quickly.
(b) depreciated after that raid ended, so you didn't feel forced to wear old gear because the bonuses were too good.
(c) actual interesting bonuses that impacted your gameplay and not boring setbonuses like X does more Y type shit.
I don't see Blizzard actually ever doing that, so the best I can hope for is that they will again provide the art team the resources to create visual raid sets unique to each class.