On a lore standpoint they really can't remove classes just like that because of how ARR jobs connect to them but I get it, nobody actually cares about the lore.
I don't see a point in removing them either since it changes nothing but names.

Also, I don't see the point of separating SMN and SCH anymore since they each have their own job skills/traits to go for and level 50 content is long obsolete to even care. Bonus attributes also don't exist anymore.