With the quarantini flavour of the season, impending Greenskins update and not-even-announced next release of Total War Sagas: Troy, I reckon TW: Warhammer III will be mid-late 2021 at earliest. :/ I really want to see what they do with all the races left to go: Kislev; Chaos Dwarfs; Chaos Daemons; Ogre Kingdoms, all filled to the brim with juicy stuff, especially the Chaos Dwarfs with their Lore of Epicly Tall and Spiky Hats(!)
I really wonder what WHI/II race Lords they'll hold for WHIII, 'cos there are only a handful per race by this point. That said, they could very well do a Nakai for most races. Hoping they bring in more Legendary Heroes, too, 'cos every race should have access to them very easily (really want to see Ramhotep the Visionary, 'cos he's quite amusing... for a Tomb King character that is(!)).