That's an argument for approaching things with the information we have now, and adapting it as and when it actually shifts, if it does. Which is what's already being done.
It's not an argument for excluding an already marginalised group of people from competitive sport - and you've already made the point that competitive sport is something our society places importance on - now, on the grounds of individual speculation unsupported by data about what might happen in the future, which is what you seem to be advocating for here.
Even in that brief paragraph, you've raised far more complexity than you perhaps realise; putting a distinction on 'going through puberty with male hormones', for example, suggests that a trans woman who was able to take puberty blockers should be treated differently to one who wasn't.
But, again, the thing there is, there is plenty of actual scientific research that has been done, and is being done on that. Guidelines and rules are drawn up by sporting authorities based on that science.
Which is how it should be done.
If you really disagree with that, I genuinely don't know what to tell you, as I don't know what to tell anyone who doesn't agree with that. It should be clear that excluding an group of people en masse from competitive sport should be a last resort, only where it is undeniably the case that not having done so is detrimental to all. It should also be inherently clear that we should be setting rules and guidelines primarily based on what has actually happened and is happening, not on what people, often irrationally, think might happen, and it should be obvious that we do so with an approach rooted in objective science, not subjective prejudice. Do you really not agree with that?