They had one in 2019, but perhaps another Skaven box, this time focusing on Skryre? Basically a fleshed out Feast of Bones with some Stormvermin and Doom Flayers or something.
I also wouldn't mind a CoS box, though I wonder what direction you go with it. Would you make it a proper soup of Freeguild/DE/Ironweld units, or do you focus on a specific city or race?