I forget which book but there is also a conversation between Dorn and Sigmisund about the wasted lives and lost potential after starring at the vacant XI and XVIII plinths in the palace. As if he remembered their respective destructions. I think there was even a theory that the blood ravens were one of those chapters. Spoken by a chaos sorcerer. 

 Ya, Its safe to say that whatever happened they were probably disbanded, destroyed and re-intergrated into other chapters. And it all happened fairly early in the crusades.