Sos 2 damage scales heavily so it's not really a combo tool as such, nor a relaunched.
However, what it does do is work as a nonbreakable anti air off a 3 way guessing game.
Application;
A) Full screen zoning: we now have 5 tools that work in unison for full screen zoning;
1) sand grenade - knock down, low hitting
2) money shot - overhead, can change trajectory up until the last second
3) sos 3 - pressure tool (also now his best meter builder)
4) sos 4 - spin shot to catch neutral jumps (evades both money shot and sand grenade and last shot of sos3)
5) sos 2 - pretty much a 45o angle that will blow up any jump forwards. The new juggle properties allow us extra frame damage to control space even better, in the time it takes for them to land we can drop caltrops (to build meter) and do any of the following; run in for pressure, stay put and continue zoning, close in slightly whilst still remaining in zoning range.
B) blowing up jump forwards attacks. Now that opponents actually have to respect all 3 options, we can start conditioning them to respect lows and therefore jump. Previously we had to meet air to air or d2 or db4 (hard reads), all of which where not always reliable, this is no longer the case - now we blow up any active frame aerial moves clean. And we get combo opportunities. And we can pretty much do it on reaction.
C) corner trapping; our corner control just got a whole lot more devious. Thanks to the buffs, we have just enough reaction time to db1 into so stance and hit 2 (we can do this last part late too allowing us to bait a jump in with so stanve itself) should our opponents try jumping out. This works incredibly well in conjunction with b4, f1 and f2 helping us effectively trap our opponents in the corner and keep the pressure on
Tl;Dr; sos2 isn't a combo replacement tool, use it for corner trapping and reaction AAs instead.