We can see that up to now Facebook and Google have not issued their own coins. And this is only a rumor and there may be some fees paid to advertise on Facebook.
That's true but that rumor might come true, there is a new rumor also the samsung with their new phone s10 is adding a crypto wallet.
With that to come true, I guess that will ignite big companies such as facebook and google to ride with with it, I believe time will come they will adopt.
Such giants will work only with their cryptocurrency, it is not profitable for them to add someone else's, why give such PR to left-wing products, if you can make your product top-end