In the first place, I thought the use of any hormone by athletes is an automatic disqualification. Trannies have take them by the fistfuls
I just tried to find out of that was still true for testosterone, but I have timed out on my internet searches without finding a clear answer. My current guess is that the absolute testosterone level matters, not how one acquires that testosterone level. It is now possible for biologically female athletes to be disqualified from the Olympics because they have a too-high testosterone level:
It seems to me that these Namibian women, IF they are biologically female, should be allowed to compete whatever their natural testosterone level, while biological females who take any testosterone should be disqualified. However, I do not think that either rule is currently in effect. Just my guess.