I don't think so, I asked CPLR about that he said that he increased the dihedral in the Axiome prior to the WC's. I believe originally it was built with a flat top wing, and they cut it in half and added a couple mm.
I think the newer planes have the wing so low in the fuse that they need more dihedral than was common in the past when the wings were closer to the engine line.
ORIGINAL: Rendegade
One wonders whether the increasing amount of sweep has some effect on knife edge flight, giving the aircraft more effective dihedral. Maybe it means that you can get away with less dihedral in the wings, which i have to say I'm not sure is such a great thing.
It's been proven before that an aircraft with no dihedral doesn't knife edge as well as one with dihedral (just enough, not too much that it rolls out) due to the extra projected side area given by the wings.
Food for thought though.
I too find it a little hard to swallow that more sweep will aid rolling and stalling.
It does however shift the MAC aft which may be desirable.