Getting rid of the current card system isn't likely to happen, and it is even less likely it will be reverted back to what it was. It will very likely undergo some changes though, and whether those or good or bad is yet to be seen. I'd honestly let go of the days that cards gave out varied buffs.

What I do know is that the card mechanic continues to give AST a very high APM. With healing as is, you would think that this would be favorable, but when a lot of those actions involve choosing different party members it gets real clunky real fast. I use a controller, but I would imagine even for KB+M players it still causes a slight delay between actions, which adds up over time.

I am guessing this issue is probably what will be addressed before doing anything different with the card effects, and a rework would involve designing the card system to reduce AST's APM. As a player who uses both SMN and NIN, I can say that the reduction to their APMs has really improved their playability and feel the same approach to AST would yield a similar result. I believe a lot of players would agree that it does make them more playable, but not necessarily more enjoyable, or that it feels slower. This is what I am expecting with 6.0 AST.