It seems FB is struggling to find developers.
Why they want their product on blockchain is unknown at this time but it does seem to be the way of the future.
So FB can dev their own & roll it out......or
They could just buy an existing blockchain that is up & running.
The question is who owns Steem? is it just a few people who own a large stake in a decentralised platform?
is that fundamentally any different to a few large owners of stock in FB?
Would FB buying out a few large owners be a good or bad thing for Steem?
Time will tell
https://www.newsbtc.com/2018/12/16/facebook-blockchain-arm-booms/