Of course yes.
But it doesn't matter whether it will be Nadal or not.
Under the current homogeneous tour surface conditions(post 2003),
next great player will reach 20+ slams, IMHO.
I would say within a decade or two maybe?
Then whole new discussions will arise on who the real open era GOAT is.
I think Federer knows this and he will try his best add more slams.