I think you're right. Apocalypse as a creepy Mummy-meets-Merlin figure is fun X-Books, but honestly, magic & Excalibur have never been a "thing". Yes "magic" was how Roma & Merlin did crap with the CB Corps, but Excalibur itself was more of a fantasy adventure book than one that dealt with ritual and magical fundamentals. If Howard DID write a treatment on Mutant Magic, it was editorial's failure to saddle her with Captain Betsy and the Braddock retinue.
I for one had no idea Hickman dissolved the CB Corps. A madcap book that has Betsy & Co go crosstime to recruit a new Corps that relies less on Otherworld but more communication and assistance would be an Elizabeth story: transition from traditional Empire to contemporary Commonwealth.