Well, duh. And how these two things even connect? xD And yeah 9.3 or 9.2 is ending, what you expect, 9.4 and 5 seasons?
Imo regular Blizzcon will be November next year and early '22 event will be something similar to Gamescom (I mean these Gamescom where Blizz actually bother to show something new) - they didn't even called it Blizzconline in blue post. For WoW I see two scenarios that could work (of course there are also scenarios with smaller or bigger fucks up):
1) 9.2 on January (well maybe patch on December, but season 3 will definetely be January), no 9.3, expac revealed on this small event, Beta/release schedule similar to SL (late Fall '22 release).
2) 9.2 on January, 9.3 revealed on event, 9.3 on June '22, on Blizzcon reveal of 10.0 + Wrath Classic, Wrath launch Q1 '22, 10.0 schedule similar to BfAs (so again late Summer '23 release).