Personally I don't like the decision but I guess it's another way of making you think more about what abilities you spec your characters with for certain battles.
Which is good I guess but it kinda comes off as a needless handicap to players who are at high or max level.
Although seeing as the majority of the 200 abilities are Passives there probably won't be much of a selection of Action Abilities.
They probably designed it so every class have about 10 to 15 (If we are lucky) Action Abilities to chose from. So the restriction might not be too bad.
It just seems like a weak/artificial attempt at trying to add another thin layer of depth to the combat IMO. But this is just my impression so whatevs
It will all depend on how fast & easy it is to switch load outs to prevent it getting annoying/ tedious. If we have to bend over backwards (can only switch at camp) or jump through loads of menus to do it then **** that noise