I think the salient point here is the M1 is just like any other ARM processor that apple rolled out and sadly people misunderstood the marketing of this, and assumed that we'd see a flood of iPad Pro exclusives, either in apps, or special OS features.
This is just an assumption, but its my belief that the IPP market share (compared to the other iPads) is so small I'm not sure its worth Apple's investment to roll out specific products just for the iPad Pro.
I mean, as mentioned earlier in this thread, they have a MacBook Pro, (had) an iMac Pro and still have a Mac Pro. None of these got special attention from apple, where they provided special features in the OS or Apps would only run on those "pro" machines. Why would we expect anything different?