No, it's highly unlikely, at least not in the same manner, because they're for-profit companies. Steemit, at least in it's current iteration, doesn't really have a profit model built in. The "profit" comes from the ownership of STEEM and the continued speculative value of the market demand.

Facebook could do something similar to that and hold a portion of the assets. However, this would likely come at the cost of their current revenue model.

I just simply do not see this happening. There are really way too many factors.