Alright so there's no watchOS 1 template in Xcode8 anymore (I'm using beta 6).
However when trying to deploy an exisiting watchOS 1 app to the simulator I could only get it to work with the watchOS 2 simulator not the watchOS 3 one.
I saw in Xcode 8's release notes this comment: "WatchOS 1 apps may fail to finish launching on Apple Watch devices" but I would like to know if it also applies to the simulator and if it's confirmed that watchOS 3 supports watchOS 1 apps.
Cheers.