I think it was only Mavic that officially required chamfering the faces of the BB shell, thus they sold the chamfering tool to dealers and the public, which I think why their BBs did not sell too well, and you can still get the easily new, at reasonable prices.
Not sure if the other manufacturers did the same, but it really makes a lot of sense to chamfer the BB faces to maximized support and stability for the BB cups if tapered bushings are used.