I think the 2 minute meta is fine, but it's important that what you do within those 2 minutes is fun. 6.08 Samurai is the Perfect Example, since you have a 2 minute Buster but you also have that layered and satisfying Resource Management, which has been removed in 6.1.. Also kind of the same with NIN, though not straight up removed they just reduced the NIN Rotation in terms of priority to 2 buttons by stripping Trickattack off it's unique-ness shoving it to mug and maging Trickattack boost personal damage ._.
imo in oder to "fix" NIN, I'd just switch the effects of Trickattack and Mug, done. But also GNB is so weird to play now.. why doesn't Double Down line up perfectly with Draw!? ugh.. Dawntrail better be Good and not a Darntrail!