I already pointed out that will be the case... Angband will very soon have lost most of it's protagosists.On the other hand, possibly storytelling will soon focus more on men and elves and there will be little Angband story to tell anymore...
Gothmog dead, Boldog dead, Sauron exiled, Thuringwethil dead or exiled, Draugluin and Carcharoth dead...
Leaves us with Morgoth, Glaurung and Ancalagon so far.On the other hand i see little opportunity to build up some Orcs, Lug,Orcobal, Balcmeg and Othrod die in Gondolin, possibly in the Huor-season, Boldog and Gorgol possibly die in the Beren and Luthien season...
*shrugs*
If we have one or two edain-seasons before we come to Hurin, Huor, Beren and Earendil... maybe we won't need that many main characters in Angband at all?