Stop those followers!
A quick PSA:
Don't level all your followers to 100.
I've been digging through the web, and it looks like those of us that have done so have experienced a DRASTIC reduction in missions - I have six. Four of which, I'm not qualified for. Compare this to two days ago, when I had an average of 13 missions available.
Keep one follower at 90-95, and another at 96-99. That is, assuming you still want those lucrative, lucrative garrison resource missions. From what I read on the web, this solves the problem and repopulates your mission list.
I'm reactivating one at 95 now, and tomorrow a 97 - will let you know if it works.