You actually expect more "massive" fps action than in pubg/fortnite and their ilk?
Tech to solve mmo/fps latency problems... rofl.
Just introducing multiplayer like co-op is a problem, 10s of people is huge problem, 100s of people is current limit of mmos and games and you are talking about singular games as usually all mmos instancing is far far far more stingy about player count.
Double that problem if your game tries to be something more than painting with roll dices. Say you want to simulate stuff like ballistics, huge open world, many systems to interact etc.
And now SC. They want 10 000s of players without any instancing playing together with AAA graphics with simulations and so on.
In order to solve that problem they had to basically research online tech and design something that was not yet even once tried by anyone. They are basically charting roads here for everyone else.
And it is not problem that is "solved". At any point there might be some problem coming up that will not be solvable without complete rework basically sinking their whole ship.
So yes it is massive problem that requires new tech to solve.