One of the key differences between Facebook and LinkedIn in mobile is that Facebook only makes money by selling ads (or to a lesser extent payments/games). It’s still early days but ads aren’t a big money-maker in mobile – and may never be. LinkedIn, though, uses mobile, to extend the value proposition of their recruiting solutions and premium content revenue streams in addition to ads. It makes for a better experience for their users, which drives other revenues down the line. Facebook makes no money – in fact they lose money – the more their users engage with their service through a mobile device, which will inexorably increase between now and 2016. So they need a path to monetizing their 845 million monthly users in a mobile environment and selling the phone is one way.
The article seems built on the idea that Facebook have a burning pile of money and need to buy something, if you start from that assumption then Nokia might make a rational choice. The problem is I don't think Facebook need to buy either Nokia or Yahoo (which is also argued in the article). They are not only one of the most popular apps on Windows Phone (and iOS and Android as well), but have a deep integration in Windows Phone through the People Hub and sharing menus.
Still, stranger things have happened, and this at least has some synergy