Sanctuary is an in-progress game that's heavily inspired by Supreme Commander: Forged Alliance. It does use Unity though. Not sure how the recent pricing changes will impact the game's development.
It’s a shame! I’m probably the least of a gamer of anyone I know (a bit of FIFA on PS4 is the only game I’ve played all year), but I played the shit out of RTS games back in the day. There was something wonderful about opening up StarCraft, jumping into a really fun and intense game, and then being finished 45min or so later. I just couldn’t get as into games you had to play for significantly longer or with more nebulous objectives. Endless unwinnable games like WoW were my absolute nightmare.
Starcraft 1 is still quite active on the Korean server, though it's not for the faint of heart.
There's a bunch of cool ones in development, actually: Beyond All Reason, Sanctuary, Tempest Rising, DORF, Immortal Gates of Pyre, Stormgate, and ZeroSpace just to name a few.