As listeners we are not "entitled" to be treated with respect, but it sure goes a long way in keeping us as listeners and keeping listeners in the loop of major shifts in the show is what I would call respectful. The show on Mule is a different show now, JG is trying to own it and do his own thing with it and there is nothing to criticize there, but it does show a lack of respect for the existing listeners to not at least hint at the changes and give the other host a chance to sign off for the listeners and close the loop. It's not right or wrong, it's simply a choice, just like the choice we make to listen or to leave comments etc.
I am grateful to Dan for filling in the blanks so listeners are no longer distracted by it. I think it's critical to note that he did a masterful job in phrasing it so as not to generate any animosity on the part of the listeners (or between himself and JG) and that's probably the most important aspect of what makes what he did "respectable" versus something to criticize and/or dismiss as a PR stunt.