It is inevitable that this would happen, he was waiting to see if bitcoin would die, but as it has come back to life again a bull run seems like a certainty. Good times ahead for FB
Why would they wait for Bitcoin to die? They aim to serve a whole different market with their stable token. I would even like to say that the longer you wait, the more of competitors there is in this industry, but considering that there isn't a legitimate backer of stable tokens yet, Facebook could be up for some success as first mover.
If they end up gaining a crazy amount of momentum, it's going to be interesting to see how the government will react. I'm certain that the counter reaction won't be pretty at all.