Something I've learned over the years, it may not have been abrupt at all, but could have been planned. Either because he decided it or the corporation decided and it may have been decided weeks in advance. There's no obligation to inform anyone of changing personnel at ETI.
Oh, I know there's no obligation, and there may well be restrictions on what Karl can say. That's why I said "It would be nice if Karl felt free. . ." Likely he doesn't.