All the features of Lightroom Mobile are available on all iPads.
No-one can tell you anything about future developments. Those who know are under NDAs, those who aren't under NDAs don't know.
Additionally, you can also already edit RAW in Lightroom Mobile on photos taken with the in-app camera (12MP ones) and photos uploaded with the Camera Connection Kit.
It is very important to realize that LR/mobile is NOT the same thing as Lightroom. It misses a lot of features. It is great for on-the-go editing if your needs are quite modest but it is not a full raw editing solution. It can read raw files through the sd card reader or through the mobile app shooting dng itself and it can do basic edits. If you're interested I wrote a little review on a mobile raw workflow with an iPad Pro a while ago here: Jao's photo blog: A mobile workflow with Lightroom? Some things have improved but most of the problems are still there. Adobe is adding features slowly though and I am sure the intent is for the mobile app to become fairly full featured. However, for most people I would currently still recommend a small laptop instead of a tablet for on-the-go editing.
Ultimately, I am aware Lightroom Mobile isn't the same as Lightroom on a laptop/computer and that some features are not (yet) available on Mobile. The day will come no doubt where that changes but for now, despite the improvements in the new iPad Pro release, there is still the gap between the two.