If this is going to happened it will be really hard for the FB coin to enter cryptocurrency because this is a very fast rising market and FB coin is just a centralized stable coin which we don’t know if they can handle crypto market. I think that this advertisement is just used to make money like to make their company popular. I’m sure that they will not enter cryptocurrency but right now they are earning ton of billions. But if they do they will be just like those altcoins who tried but failed miserably but I don’t know that really I guess we just have to wait and watch.