iPhone XS and XS Max

Does anyone know what XS and XS Max return from FIOSPlatformMisc::GetIOSDeviceType() ? (Looking at 4.20 and dev branches on github and nothing in there yet for XS models)
IOS_Unkown or IOS_iPhoneX?

I also really need to know this!

It returns IOS_Unkown as all XS/XL models are major 12.

Support for iPhone XS, XS Max and XR has been introduced in 4.21 (you can check this now in Preview 4).