My expectation is that the 10.2” model will be a lower end model, and a replacement for 9.7” models, but it won’t be entry level in 2019. They will keep the 2018 9.7” iPad model around as the entry level.
Everything is going Face ID. The eventuality is Apple will no longer sell Touch ID-only models. They may eventually sell ones with both Face ID and under-screen Touch ID, but ones with Touch ID alone will likely become legacy. The migration to all Face ID has already started with the iPhones, and at vastly different price points. Apple sells the iPhone XS 64 GB for $999, but also sells the iPhone XR 64 GB (which actually displays 22% more information on screen, same as the XS Max) for $749. Furthermore, if you want more than 64 GB, it’s $1149 for the XS 256 GB, but only $799 for the XR 128 GB. For the XS Max, it’s even more, at $1099 for 64 GB and $1249 for 256 GB. IOW, if you want the number of display points that the XR and XS Max can display, and you also want more than 64 GB, you have to pay 56% ($450) more to get the XS Max over the XR.
It’s clear Apple is perfectly happy selling a Face ID model of their iPhones for much, much less money than their flagships, so it shouldn’t be a surprise if Apple does the same thing with the iPads. The question is not if they will do this, but when. I just happen to be guessing 2019, but others may think it would be later.