I'm all for bringing more MacOS features to iPadOS but I'm not sure how much farther Apple can go without allowing workflows that require the use of a keyboard and/or mouse. Up until now, Apple hasn't crossed that line and it looks like they really don't want too even with the release of the Magic Keyboard.
For example, how do you add the type of external monitor support that everyone, myself included, want without requiring the use of a keyboard/mouse to control what's on the monitor? Likewise, how do you port XCode to iPadOS while still maintaining the "everything can be done with a finger" rule? If Apple's going to allow those kinds of things, it's not much of a stretch to start talking about things like a MacOS-like UI when docked, merging the two operating systems, or just allowing MacOS on the iPad. I voted the "keep them separate but improve iPadOS" option but I'm not really sure what the right answer is for the iPad.
I'd love to be able to walk the engineering halls at Apple and see all the various combinations they've tried out. They most likely have prototypes of everything ever suggested on this forum. They probably have iPads running MacOS, touchscreen Macs, and everything in between. I'm curious what they'll announce at WWDC but I think a lot of folks here are going to be disappointed.