We've seen this plenty before when a previous champ realizes the new champ has his number. A. Silva has fought at both 170 and 205 before.
Franklin eventually moving up to 205 (or catchweight fights at 195) after realizing he could not beat Andy.
Faber after being owned by Aldo.
Couture back to HW after Liddell started owning the LWH division.
Fighters (not necessarily previous champs) moving down in weight when they figured out they had less than a zero percent chance of ever beating GSP.
Weidman owns Andy and that is not going to change
I'd say 205, a lot more lucrative match ups for him there.
He isn't going down for damn sure. Is a lot of interesting catch weight and LHW fights out there that people would pay to see. 
StrikingMMA - I doubt he will change weight class for the same reason those guys did. They did it to pursue a belt. I don't think Anderson would do it for that reason.
If he comes back (which I doubt). I think he will either do it for a couple of super fights or he will do it just to go out on a win or two. I can't see him trying to climb a mountain again.
I agree with much of what you have said. But because of who he is, I don't see the UFC making him climb a mountain, like other fighters, to get a title shot in another weight class. It would be great for business if they could get him back in the spotlight and as a potential winner of a belt in a 2nd weight class. I could see them only making him win one fight against a top contender and then letting him fight for the belt. Not saying he would win either fight, though.
circa305 - Hes not coming back..