I am picturing the uniforms as having "trip wires" that basically alter the air flow to make a suit faster. While it is common to think that a smooth surface is more aerodynamic, that is not always the case. If you can "trip" the flow of air you can improve the drag.
I was involved in wind tunnel of trip wire suits for cycling and speedskating prior to 2000/2002. There was a measurable effect of the trip wires at cycling speeds. A problem is that the rules of the UCI (and in Alpine skiing) are more explicit than the rules appear to be in luge/skeleton. We even talked about asking the suit manufacturer to sew the seams in specific places and in a specific way to where it might pass the rules (basically sewing a seam "poorly"), but in the end 1) the US did not have anyone good enough in track cycling to where the time savings made a real difference and 2) the US had already gotten on the bad side of the UCI with the 1996 Superbikes...
I am in the camp of "If the rule does not prohibit it, then do it until the rule is changed". If there is not a rule against it, you are not breaking a rule. In some cases it comes to interpretation and if that is the case then you get an interpretation to clear up the matter.
One reason that a sport might not want to increase the speed is that the danger of someone getting seriously hurt or killed increases with speed. That is the argument alpine skiing used.
(Not sure if the rule is still in place in alpine skiing although I cannot recall seeing anything that looks like trip wire tech).
I was pretty amazed at the difference in drag coefficients from different materials at cycling and speedskating velocities. The suits that were tested were the exact ones used in 2002 by the US team. After that everyone else figured it out and the playing field was leveled once again.