I want to be clear that when I use the term "reboot" I am talking about returning to the same time frame, retelling a similar story with new actors in the old roles.
I would be totally on board with the original cast set 15 years in the future from Serenity. I don't consider that a reboot, to me that is just a continuation of the original story. No different than say Star Wars Episode VII. That was not a reboot to me, that was just continuing the story.
The new Star Trek movies are more of a reboot to me.