So far, I've found one:
There's a chance that the Facebook rumour came from someone. But this one? Just totally absurd rumour that he must've been trolling. Like for that rumour to literally have some slightest merit, it could've been at least an old quote from Satoshi himself.
Before we believe on that we really need a strong evidence or source that will make that statement legit.
If facebook will ever engage in cryptocurrency like bitcoin then it can be a possible positive effect in bitcoin's price in the market and people will panic.
But before that, to see is to believe, just state his sources and we're ready to absorb his information. Rumors are only just a story without proofs.