Literally yesterday I was thinking how there are 0 RTS games in popularity right now. I guess SCII kinda counts, though it's mainly popular in Korea, but WC3 literally spawned the most popular game(s) in existence: MOBAs(LoL) and WoW.
Also non-Blizzard news, Age of Empires IV is being developed too.
It has TFT: "Relive the events of Warcraft III: Reign of Chaos and The Frozen Throne. Command mysterious night elves, insidious undead, savage orcs, and noble humans as alliances shift and cultures clash in ruthless conflict. " from Playwarcraft3.com