My thoughts on these items:
Master Ball - would probably only be available at an event in very limited quantities. It would just be too overpowered.
Ultimate Raid Pass - one of these will probably arrive eventually, maybe in a different form or another seven day streak reward (other than evolution items).
Egg Incubator - I doubt these will ever come, Niantic just want that little bit extra money.
X Attack/Defence - good concept, but would there be a limit on how many you could use on one pokemon? If it arrives, there would be a lot of technicalities.
Poke Radar - there will probably be an improved nearby list rolling out in the future, no real need for this to be introduced.
VS. Seeker - Why need this if PVP is coming soon? (probably soon)
Aspear Berry - This one might be introduced, but probably just drops from stops.