I feel like there’s been little going on in RTS land. Did I miss any significant releases?
AOE2 gets balance and content patches about once a month. It's remarkable on its own that a 20 year old game is still getting balance patches. I suspect this is a due to a mix of evolving strategies, a changing skill-level distribution, and feedback loops from subtle changes, catalyzed by added units and civs.
Likewise, most of the biggest pros and casters started their careers 5-10+ years ago working on community tournaments and other grassroots events. Even though there's a lot more money now with investment from Microsoft, Red Bull and others, that grassroots core has stuck around and feels (at least to me) more fresh than the very corporate machinery around Blizzard RTSes. It's funny to think that the most anticipated LAN tournament is literally held in someone's apartment (https://www.ageofempires.com/news/nac3-tournament/)!