Damn, I forgot. Then just apply what I said to the Emperor learning of Luke. Sounds like there is a book explaining when HE knew and could then tell Vader.
So will D+ have Vader know before and he was just playing dumb to the Emperor? Given time, I'm sure will happen. Vader will find out, OBW will make him think it was bad info. Vader will find out AGAIN, OBW will trick him that Luke is dead already. Round and round we go. Stuff like that is the kinda soap opera stuff we gotta deal with in a TV series that's a prequel to something that has a pre-determined outcome. Clone Wars walked that tightrope pretty well TBH but best to not tempt the fates again.
Best to just jump well ahead or behind and start fresh IMHO. Even the Asokha show with probably Thrawn in it will ultimately go nowhere because the ST has none of that stuff.
About the only thing left in SW film canon I would be interested in seeing is WTF these "Knights of Ren" chaps were all about but I have zero faith D+ could make them A. interesting, B. legit threatening, or C. fit in with what little we saw of them in TFA and ROS. I'm not even sure what the end game with Mando is other than be a launch point for other shows at this point.
Lucasarts should just take the 3-4 characters they are most interested in, have them all get frozen in carbonite together in a freak accident, and then be thawed out 500 years in the future with all new characters and a coherent storyline that won't bump into a skywalker EVER. Re-envision the Jedi/Sith dynamic, give the galaxy a new existential threat, and get back to swashbuckling space adventure!