Ackbar looked like Ackbar to me, and if they got his original voice actor back as someone else mentioned, awesome. Maybe we’re finally getting used to CGI characters. 😉
As for the Vader worship thing, Snoke may have twisted the facts and made Vader into a noble martyr. (Which serves as public propaganda as well.) If Luke and Leia have been less than honest about the Sith skeleton in the family closet, that may have made things worse. It’s unlikely they have made it public.
Unless it’s officially said Han was told who Vader really was, that’s in doubt as well.