The claim here is a naive realization of existentialism. I'm not sure how much value examining the self in terms of social media adds to the discussion other than the parlance of our times. I don't think people do anything on Facebook that they haven't done through more conventional means. The only thing that's changed is the speed at which they do it. Exploring that difference would make for a more interesting piece than what was posted.
I think the ho-hum responses so far to this article are because it leaves out what philosophers take for granted, which is the "stakes."
Is fb an imaginary land where words have no meaning? (kind of like 4chan) Or is it a direct extension of our reality where our actions have consequences, like being at our job?
We may not be able to even answer this question without comprehending what heterotopias are:
We tend to automatically think fb is a digital/optimized/enhanced version of every day life with the same responsibilities, ability to do damage and ethical consequences as our everyday life. However, in practice, fb appears so completely dissociated from reality that we can't expect people to be responsible for their actions there any more than we can expect Miss Piggy to go to jail for punching Kermit the Frog. [1]
If all someone cares about is acquiring users and serving timely and relevant ads, none of this matters. But people who care about designing a platform for a species to support for their entire lives, directing and controlling the platform is critical.