The geo-political landscape resulting in the best decision for the FWL being to not get involved would be irritating for very similar reasons to FASA's handling of the FWL in the 90s.
I'm not suggesting that's what's going to end up being the case, but you at least see why that would be irritating, right?
Sure. I'm strongly for the FWL retaking Wolf worlds, even if it fails and they get burnt for it, just because I dislike the idea of having a power be able to strip every last bit of military force from their borders to do something consequence free.
Heck, it doesn't even have to be straight-up conquest. Have some of the planets try to overthrow their Wolf administrators. Like the Republic worlds the Wolves just conquered--if the Wolves brought all of their military to Terra, some of those recently conquered planets would probably attempt to re-establish some sort of Republic rule, right? Or Solaris. There's gotta be some sort of underground resistance there that'd fight to go independent again.
And heck, for all the Lyrans/League knows the Wolves have abandoned yet another OZ to go setting in some other part of the Inner Sphere...again.
I guess Alaric could send out some sort of warning to Lyran/League leadership saying "don't touch those worlds, I'm just stepping out to grab Terra, I'll be back"--at least then it'd be somewhat justified for those two somewhat fragile Successor States to hang back for a while. But if no message goes out, how long can the two states avoid taking over any of their ex-planets before things get a bit silly?