Yes, there would still be a difference in masts, as the dies used in extrusion got worn out. But the playing field for the pro's would still be level, as they all searched for masts of different stiffness and could choose the profile they believed in. The rest, who does not have olympic ambitions, could live in the belief that we had the same equipment as the pros.
Now everybody are stuck with a stiff carbon mast, and has to adjust to it, instead of finding a section that fits their weight. Interestingly enough, I have not heard or read about comparisons of the speed between the two. Not even before the ballot. This season, we was clearly faster than a T with the carbon stick, so it's not an essential on the hobbyist level.

(In addition, lots of sailors can't afford to upgrade, and further degrade their motivation for participating in class events. But what is, is. So..)

I guess the competitive weight is still from 135Kg to 160Kg (ca.)

There was an article in Seahorse, where Juan K. wrote about a reiteration of the Star design. He was playing around with keel placement and volume distribution within the one-design class rules. There are some room to work within, as the rules often allow some margins for homebuilders. With todays CNC plug shaping, it gives the designers enough room to make a difference in the hands of olympic quality sailors.