That's a risk with any sport at elite level, I think. If you're going to make the grade then it needs to take over your life, to a great extent. Swimmers get up at stupid o'clock to travel to the nearest decent-sized swimming pool (which in this country is often a looooong way away) before school and then again afterwards. Footballers have academy systems similar to those in rugby. Rowers... well, actually rowing's not so bad at school, because it's an even later development sport than rugby, so the lifestyle privations they take on if they want to compete at the highest level are accepted as adults. And probably so forth for other sports. And in all of these cases most of those who put themselves through those years of hard graft, putting the sport first, sacrificing friends and family, won't make it, because there just aren't enough slots.
I remember a passage in Fever Pitch (OK, football, but it's the same general point) where Nick Hornby is talking about some boy he used to come up against at schoolboy football. This boy was head and shoulders above everyone else, appearing virtually another species compared with the others around him, who were no slouches themselves (Hornby goes on about this for a while, but you get the point). He wound up struggling to hold onto a place in a Fourth Division team, because there were others who were even better.
I hope none of my DCs do want to play sport professionally, because it strikes me that for most that's a very difficult road. I hope they enjoy sport; I hope they find a sport they love and can keep playing well into adulthood. But I'd rather not face the dilemma you're facing at the moment.
If you do get approached by an academy, perhaps you could talk to some of the other parents about how the lifestyle works out for their DSs?