Short answer: WeWorks valuation is shaky and depends on the executive team in 2018.
WeWork can defend and go above $20B if they make some important changes or they can become a cautionary tale of expanding too fast.
It's a great company and concept but it seems clear that they are losing steam as they grow. Many of the new offices that I have visited in the United States and Europe (since many startups choose WeWork) have the same level of quality in terms of features, on site staff, services, usable space, or even decent layouts. It's a sign of falling quality in their real estate location strategy which will impact them as more competitors come into the market with smaller more thought out portfolios to offer customers.
I would say WeWork has a solid chance at defending it's $20B valuation and growing it if the executive team rethinks their locations and offerings to remain competitive. It's a startup going thru growing pains but it's $20B valuation will come under more scrutiny in 2018 without a doubt. #weworkvalue