Given the graph in the article, it wouldn't surprise me if Facebook made another get-all-users-so-it-doesn't-threaten-core-business acquisition a la Instagram.
Although in this case, Facebook tried making a Snapchat clone (Poke) and failed miserably, so such an acquisition might show a weakness in Facebook product strategy and be somewhat embarrassing.
I would love to see Facebook try to acquire Snapchat. They were so arrogant when they launched Poke, claiming they made the entire app in 12 days. I thought it was pretty low to make a full blown copy of Snapchat.
I actually wonder to what extent Facebook really planned Poke. The way it was always described, a small team built it over the course of a weekend- I can see it being a random project people decided to do that got launched without any major strategy behind it.
Snapchat was likely trying to value itself in comparative terms to Instagram. Instagram was a threat because it had both the meteorically rising product AND the engineering team capable of scaling ahead of that growth. I think Facebook created Poke not to compete directly, but as a response to the comparison to Instagram. Facebook "coded Snapchat in a weekend", literally.
Although in this case, Facebook tried making a Snapchat clone (Poke) and failed miserably, so such an acquisition might show a weakness in Facebook product strategy and be somewhat embarrassing.