cause we can do False Emperor before Ilum.
The class story is iirc intended to end at level 47 and you can join FE SM with level 48 so just because we overlevel it doesn't mean the lore isn't in the correct order.
As an example I brought my 2. Ops to lvl 55 only with FPs, my class story is that I should go to Balmorra but I can still queue for OPs and the new FPs.
That doesn't mean OPs should be runable at level 16 because lore isn't relevant