I love TouchID, but if FaceID does the job as well, I'll take the extra screen instead. The 10.8" iPad, all display would be great.
To keep screen resolution and app ratio of a multiplier we may see the following as it was mentioned a while ago when the increase of the 3.5" screen was increased to 4" and the 7.9" iPad Mini app scale was that of the iPad 9.7". Expect to see:
iPhone X 5.8" = iPad Pro 11.6" (presently 10.5")
iPhone X + 6.45" = iPad Pro 12.9"
iPhone X 5.25" (presently SE) = iPad Pro 10.5 presently (may be replaced with a future iPad Mini 10.3")
Line up will resemble and reflect the pixel for app multiplier with Super Retina Resolution:
iPhone X (SE) 5.25"
iPhone X 5.8"
iPhone X+ 6.45"
iPad Pro Mini 10.3"
iPad Pro 11.6"
iPad Pro + 12.9"
MBP screen size should be bumped to:
From 13" to 14"
From 15" to 16"
MB 12" will see no change and once iOS matures enough may get replaced with the iPad Pro or iPad Pro +. Tim Cook has already stated that he and Apple sees the iPad Pro and iOS as the future for mobile computing, this will become more evident with minor features and improvements to macOS including hardware designs.
No point introducing the efficient and powerful "A" processors into a Mac, when you can just phase out what the MacBook Air and MacBook audience carter to with the iPad/Pro models.
I hear a lot of people voice valid concerns about programming on an iPad Pro with iOS 11, however this will become evident once Swift and XCode will run natively on iOS 12 (hopefully). Other x86/x64 apps will have to migrate to ARM, as there is a lot of unnecessary support for these legacy apps holding performance gains and power requirements.