BCR have allegiance abilities in the tome. They are mainly updating non-allegiance-abilities in the tome. (Skaven, Fec, Fyreslayers)
edit. Don't get me wrong, I'm waiting for a KO update and I know that having bad allegiance ability equal having no ability. Still KO and BCR do have them and right now only Stormcast and Blades of Rageboi got an updated tome while already have it all.
Nighthaunt, Beast of Chaos, FeC, Skaven, Slaanesh and Fyreslayers were in the gh18. I imagine Ironjawz and Seraphon to have priority, now...
Or Dispossessed 😎