I'm also hyped for Switch and i love pillars.
Let's face the facts:
-Switch is capable of running skyrym
-Switch carts size can be up to 32 GB
-Switch supports Unity engine
So The ports of pillars / tyrrany are possible from specs point od view.
The real question is if porting by obsidian or other dev would be worth of time and money and if these ports sells.
Switch is hybrid console so it seems ideal system for RPG. You can play in front of TV/monitor and you can take it on the go.
I believe that ports would do the job and sells pretty good. Maybe it's up to Skyrim to show the way and prove the point.