Isn’t that... pretty much exactly how WoW is too? That game is meta-driven as fuck. It was when I played in Mists/WoD/Legion/part of BfA at least.
WoW meta and FFXIV meta are hugely different, though. There is also no "real" build variety in WoW - there never really has been either.
FFXIV has a party meta - certain classes work well together (and multiple copies of the same class hurt limit gain in raids). It boils down to 2 Tanks (One main, one off), 2 healers, and 4 DPS. The "best" FFXIV class will only generally be 5-10% better than the "worst" class in a given role.
WoW will have wild differences in classes - 40% being the average between the best and worst. This number can go even higher with bad balancing. There's virtually nothing stopping you (even less with Personal Loot) from having a tank, a healer, and as much FOTM DPS as you can get into the raid (Balance Druid, Aff Warlock, Fire Mage) where FFXIV actively prevents exactly that.
WoW's "build diversity" just boils down to pointless newbie traps and buttons to click inbetween modes that add nothing to actual gameplay. For Arms Warriors, for example, you want "War Machine" for non-raids/utility and "Sudden Death" for raids. All you ever need to do is click the "Sudden Death" button before a raid. That's the high level gameplay he's discussing. "Sudden Death" means you can cast "execute" 2 extra times a minute.
You can also play different specs (maybe) but all classes have a clear "best" spec. You
can build a Frost or Arcane mage, but if you want to get on top of meters? Just play fire. Want to play a non Marksman hunter? You can, it's just a huge mistake to do so. Different classes also make a
huge difference in WoW. Want to be the best DPS warrior alive? Roll Fury. Want to even be better than that? Guess you're going to have to roll a new character, because Fury is still in the bottom half of all DPS.
Pretty much; Blizzard gives the illusion of choice with talents but the talents are generally so unbalanced that choosing anything other than what is incidentally "Meta" is next to worthless. WoW's combat is more freeform, largely because of the lower GCD, but there is still a rotation to follow for every single spec.
WoW's combat is free form because there aren't any rotations in WoW - just priorities. Mistakes aren't as punishing. In FFXIV there is a
literal rotation as most attacks have to be done in a specific order like a combo.