/click methods just work as sort of a global advancement of several sequence macros.

Using /click you effectively press all your sequence macros until something goes off. This can help you with giving a bit of "weight" to spells you want to go off more often and lower the chance of a stuck sequence that missed a necessary debuff for casting another spell.

My guess is this method will be nerfed and sequences with a comma followed by a blank will be treated the same as commas followed by "null", effectively stopping the comma timing without removing the capability for which castsequence was intended.

Using castsequence in the manner it is being used here, kinda works as a crutch to the multiclass teams, but they can probably be just as effective with properly placed and written cast macros. I know the only thing I use click for is to avoid the 255 limit and simplify writing macros for use with FTL setups.