He's just gone to a new flock. I re-home boys every year because I let my girls hatch every year. It's part of the flock management everyone who keeps chickens deals with.
If all you want is a flock of chickens to enjoy and get eggs from, there is no reason to not only have a mix of breeds but mixed breeds (hybrids) and let them live as naturally as possible.
Una, another SF mix. This girl was half WLH.
I have had up to 17+ different pure breeds (LF to...