I think they should do what they want to do. Not what we want them to do. I see this tour as closure for them and the fans. The end of a novel that left us hanging.
Stewart seems to relish his "role" as a regular suburban father and a composer. This tour is taking him away from his family for a year as it is.
If they put out a new album people would probably expect them to tour again. Would they want to? However, I wouldn't mind if there was a live album of the tour. They could add a couple of (hinted at) new songs to it as a bonus. No additional touring would be necessary.
I'd love to hear more Oysterhead and Gizmo.
Do what feels right fellas!