It's just getting worse for Facebook this week!
http://www.bbc.co.uk/news/technology-43514648
I think that facebook will cope just fine. The grown-ups* realise how much of a data fuck-up they have been involved in but for probably 75% of people, they just don't care, and of the remaining 25% of people, less than 1% will do anything about it.
It has no real challengers at all. Thats part of the problem.
But all it would take is facebook to offer to host all the 'youtubers' who have recently been booted from the revenue program (and give them the revenue) and then facebook would have nothing to worry about regarding page views.
Remember it is just an advertising portal. I'll be willing to guess it still has billions of page views a day.
People still buy
The Sun
The Mirrror
The Daily Mail
'We' have short memories.
*Grown-ups being people who have reached an age/point in their lives when they realise the world is very different to how they imagined it when they weren't a grown-up