I personally do not think there are millions of gamers on MAC hence Developers do not usually support that platform.
Issue with releasing games on multiple platforms (PS, Xbox and PC) is keeping them refined: a simple update has to be done 3 times but
on one of those platforms it might no longer be simple, hence some games have platform specific bugs. Adding another platform means that
a lot of resources have to go into porting it over as well as maintaining it. And as MAC gaming community isn't really big it's not worth it.
You can though use
Benchmark and run Vampyr through that. MAC's are more, in my and many others eyes, more of a work platform than
they are a gaming platform.
Hopefully you see where I am coming from, I honestly doubt there will be a MAC Release, but I could be wrong!