User blog comment:Omega natsu2/Chapter 387: Tartarus Arc, Part 4: Father and Son, Predictions./@comment-5593752-20140530150721/@comment-7418318-20140530172638

I know it's possible. I even brought up this very possibility once in the Gray and Silver Predictions blog.

It's certainly more likely - or rather less unlikely - than the Silver = Future Gray theory.

But while it wasn't rendered impossible based on the fact we have, I think it's still quite unlikely.