The other parts are good, but this isn't a helpful argument because sports are de facto segregated by morphology now; to switch morphology categories you have a possibly incomplete intervention; and all other interventions are scrutinized incredibly tightly to make sure they don't give an unfair advantage (steroids, prosthetic limbs, surgery, etc.).

The World Anti-Doping Agency rules even contain prohibitions against gene therapy that improves performance, even if it would just give you the same gene that some other competitor already had! There are no exceptions. (The technology also doesn't really exist to do anything useful in this space, but even so they decided to get ahead of the curve and forbid it.)

If you're going to argue for a total rethink of what counts as an intervention or what is acceptable, "Being tall helps with volleyball" isn't going to cut it. Everyone knows already. If you're not going to argue for a total rethink, then there's a lot more than just height to worry about.