I think that it should depend on the individual sport and what helps promote competition within it, and some sports already take those things into account. Boxing and MMA have weight classes to further differentiate groups because weight disparities create too much of a difference between fighters. The important thing is that this is viable for boxing and MMA. Some sports are either niche or really just have people paying attention to the top. No one cares about lacrosse, but it's viable at the collegiate level because it gets subsidized by other programs such as men's football and maybe men's basketball. But men's football and basketball sometimes isn't enough to subsidize other sports programs, which may cause schools to have less sports programs.
From the juvenile to the professional level, viability is the most important thing, and if something isn't viable then it needs to be funded. Most collegiate sports programs outside of men's football and some men's basketball teams operate at a loss, so colleges may offer fewer athletic programs. In America, at the professional level, this is seen with the NBA propping up the WNBA, which operates at a loss, in contrast to women's tennis, which is profitable. The issue is, though, that these other programs and divisions need to have some viability. A sport can't diversify too much.
It makes more sense just to try and normalize transgender athletes in their gender's sport of choice at the lower levels than trying to diversify sports divisions that might already be subsidizing programs that are already not viable.
