Those are pretty big assumptions
But let's say we assume they hold, for the sake of argument. Then solar systems, or more precisely, planetary systems, assuming they coalesced from the gravitational condensation of gas that initially formed the central star and that the orbiting planets result from leftover angular momentum in the system, then probably it would be planar? I'm not 100% sure. Perhaps it could exist in two distinct planes ala the clifford double rotation. But it's hard to know without more exact parameters that one could plug into a Monte Carlo simulation to see what kinds of results are obtained.
One interesting thing about a planetary system in two 2D planes is that the planets in one plane would, as far as the other plane is concerned, occupy the stationary plane intersecting at the origin (the star), so the collective mass of those planets would effectively act as additional gravity to the planets in the other plane. Furthermore, since they would oscillate above and below the other plane within their own orthogonal plane, planets in the other plane would experience an oscillating gravitational force perpendicular to their orbital plane. The net force is addtional gravity in the direction of the star. But I'm not sure if this perpendicular oscillating force would destabilize the orbit within the plane or not. Depending on the relative orbital periods, maybe it could actually act as a stabilizer? Again, hard to say without a Monte Carlo simulation to observe the possibilities.