The problem with that is that you can't do it by making straight chord slices of the the wafer - each cut has to terminate or it will go through the middle of the next hexagon. But it does sound plausible - surely lasers could do this more easily than retooling the whole lithography pipeline for rectangular wafers. But you'd think they would have thought of the idea.

You could do triangular chips with straight cuts. But I that would divide the area more finely, which is the opposite of what they need.