Yeah, it's horrible verbiage, plus it's really rather self-serving on Facebook's part.

Really this is "we noticed this user has stopped using Facebook, please trigger an action so we can spam their email to remind them that we exist." It's not about helping the user, they don't send these types of things for users who are active on Facebook otherwise, but not directly interacting with you.

"Reconnect" to a dead friend is pretty worst case, but it's also insulting to be told to "reconnect with Bob" when you go drinking with Bob every week. Facebook has incredible hubris to think that if two people aren't interacting on Facebook, it means they aren't interacting at all.