Hewitt benefited from a transitional period. nadal could have done it if he had that luck but Roger was just too good. nadal won 11 titles in 2005 while 19 years old, 1 of which a slam and 4 masters 1000.
I don't think it will be broken because of the physicality of today's game.
I've already blabbed on and on in the "no teens in the top 250" how this is absolutely incorrect. Just because you hear commentators repeat this 1000x per tournament doesn't mean that this is correct. It's utter nonsense.
And all records will be broken, if possible, so it's outlandish to say something like this will never be broken. It will, just not anytime soon.