It seems reasonable to me to believe that the Great Curse *completed* the Solars' Shaping and social defenses.
That it's not strictly a matter of *bypassing* IPP and such—-that thinking of the mechanics that let the Great Curse in as a trick or loophole to get past shaping defenses is the wrong way to think of it.
Rather, it's that until the Great Curse shaped extra form into the Solar essence, Solar defenses had the very flaws that let it in.
It feels right to me, and compatible with the described errata.
That the Solars get to be perfect and unbreakable by shaping NOW because the part of themselves that is vulnerable to the world is wrapped up perfectly by the Great Curse and its endless turning-inwards reflections of the self. Without it, they might have had a flaw of perfection that lets you do Shaping attacks compatible with their Motivation if you can obtain some appropriate level of buy-in from them first; or, if you want to stick strictly to the canon, bypassable by up to one sufficiently potent death curse that is flexible enough to find the Limit track. (That's not as strange as you might think. You'd almost *want* your shaping and social defenses open to death curses, design-wise, just to make sure that if you'd accidentally closed your *own* ears to the truth with a self-reinforcing ideological self-shaping effect, a strong enough external sacrifice could reopen them.)
I'm not sufficiently up-to-date on the defenses of the other Exalted types against such things to extend this argument to them right now.