[pbreit]

Obviously the acquisition changes the calculus no matter how independent the players claim the companies will continue to act independently.

However, I think you are quite possibly right. Acting independently does not preclude Instagram from switching to Facebook place information. There are large benefits to using Facebook data over Foursquare not the least of which is better data outside the US. And with Foursquare on perennial death watch and switching directions frequently (including very recently), switching away from it is probably a wise business decision.