The leg dangle has been a thing in MotoGP for many years now. I believe Rossi (definitely not one of the younger guys) started it, and many of the top riders followed. There has been a lot of discussion and speculation as to why they do it at the GP level with nobody ever really confirming why, but it has stuck. In general body positioning in GP racing has changed a lot vs. decades ago, I think the inside body positioning has gotten a lot more significant to the point where the top riders like Marquez are now dragging elbows on the track. It's funny seeing this topic come up here because I've often speculated that riding a sportbike is definitely not helping with my MTB cornering. Seems I'm not alone.