What I am saying
He does not have to change the hubs to go to a tubeless tire...he can get replacement rims for tubeless tires to fit those hubs..
Now if he really wants to change out the hubs he can do so..Just costs a lot more to do it that way..
Go either way that you want here..All I am suggesting is a way to save some bucks and get a good result..
I have tried most all of it and now do what is known to work..