Seems like there is an issue in Xcode 27 beta 4 & 5 where DeviceHub doesn't show iOS 16 devices or simulators. I've checked the filters to ensure I haven't hidden anything and the are listed in the Xcode destination dropdown.
DeviceHub not showing iOS 16 devices or simulators
I'm experiencing the same thing! So it's not just me.
The strange thing is that for me, Xcode shows iOS 16 Simulators in the destination dropdown, but they don't appear in Device Hub. Which means I can build and run on an iOS 16 simulator, and Xcode shows that it has launched and is running, but there's no visible Simulator for it!
I can't debug and run on a physical iOS 16 device at all, though, since physical iOS 16 devices do not appear as a run destinations in Xcode (nor in Device Hub) :(
I ran xcrun simctl list runtimes which includes:
iOS 16.4 (16.4 - 20E247) - com.apple.CoreSimulator.SimRuntime.iOS-16-4 (unavailable, The iOS 16.4 simulator runtime is not supported on hosts after macOS 26.99.99.)
So I guess that's that :/ Guess I'll have to try to get a Tahoe VM going if I can find the disk space.