Well, you've got me there... Unless OP used "PG" to refer to Paul Graham's initials and not the username. In that case the only way PG could comment not as PG would be to claim to be someone else, in which case the answer wouldn't be true.
That may depend on whether or not the double-quotes are delimiters here or actually part of the name. He could sign his comment as "PG" or PG accordingly.
As far as I know Paul Graham has never signed a comment as or claimed to be "PG" including the quotes. OP's question is phrased in a way that assumes Paul Graham has commented as "PG" (whatever that may mean) before, so if OP was using the quotes as part of the name then the question itself wouldn't make any sense. And if that IS the case then, well, I really don't know where to go from there.
I meant it in the sense of "will he ever comment again under the HN username of PG". For all I know, he might be commenting now under a different username, but if so, that's his business. Not mine. It has been a while since the PG account has commented. I was just curious if he plans to return to the PG account.
> Will you ever comment again as "PG"?