This is very much possible with grab being set to the L button as well. Changing your control scheme has absolutely nothing to do with this mechanic. Also, as @
A2ZOMG
said, this is not technically an option select. It's really just a mixup, since you have two options out of the same situation - pivoting. Whether you can do this with one button, or using the attack and grab buttons separately, doesn't change the fact that the timing and what happens (ftilt/grab) is entirely up to you and is
not based off the context or situation within the game making this not an option select.
Buts that's all just technicalities.
The idea of pivoting past your opponent with different options at your disposal will definitely have application in this game. Limiting yourself to the grab button is not a good idea though, because it removes your ability to use the options the other buttons provides. This include pivot fsmash, jab, and even upsmash, not to mention that some characters have good enough forward-b's to use as well.