Eh? I have apps that are almost 10yo on Google App Engine. Even when they forced a complete migration from the Master/Slave datastore to the High Replication Datastore, it was a pushbutton process that required minimal intervention. Honestly if I have any complaint it's that they don't force change faster.
On the other hand, Facebook's API changes at a pretty rapid pace and there are few apps older than a couple years that have survived without significant code changes. I've seen API changes that are basically "rewrite your whole app".
