And the answer is... I'm broke 😌
I was treating the center({axes:[true, true, false]}, object) like the old object({center:[true,true,false]}) which is not the case since primitives are now created centered at [0,0,0] by default.
Since the primitive is created centered by default at [0,0,0], changing the axes on a new part doesn't really have an effect.
Picking a consistent default is probably the 'right thing(tm)' to do since the old primitives where very inconsistent - round things like cylinders and sphere where centered on X/Y but not Z and cubes where created with a corner at [0,0,0].
Hopefully new docs will have little warnings for those transitioning from V1 to V2 and maybe some helpful examples for porting old designs over.