Also Google's Pixel 4 is rumored to launch with a competitive 3D facial unlocked system in October.Interesting. I wonder whether this is the whole picture. Definitely sounds intimidating for Apple though, loosing one of their USPs.
In my opinion most Android OEMs don't have a Face ID like feature on their mainstream flagships because of costs. Optical under display sensors should be cheaper and most users don't have any problems with these sensors.
Also I think Apple can't use an under display fingerprint sensor because of 3D Touch. This is the reason we are hearing rumors about Apple planning to ditch 3D touch.