You seem so sure about that; I am not. Lauda seemed to have so much personally invested in this forum that I find it hard to believe he won't return, even if it's with an alt account.
Lauda is dead - Lauda cannot come back.
It's irrelevant and pointless to wonder if they are back under other accounts. With the bitcoin experience that person has, they will probably use it. No doubt the person that operated the Lauda account is reading this - but
Lauda will never return.