He would move up to HW to fight for the belt. I'm guessing he's saying he wouldn't move up to fight random fights. It's not that hard to figure out.
Not hard to figure out at all.
"2015 will be the year I cement my legacy as the greatest of all time"
+
"I keep Anderson and GSP above me to keep myself hungry"
= Jones will stay at LHW at least long enough to break the record for consecutive title defenses
"People say I am too big for my weight class but they are just making excuses."
"I had to eat more to keep my weight up for this fight"
= I am not as big as people think, I could probably make MW without much trouble.
"I would go to HW for the right fight and the right purse."
= For a buttload of money, AFTER I have already proven everything I need to prove in my career as a LHW, I would go up for the right fight and a serious payday, not to please the haters who want to see me get injured.
"I would fight Cain in a heartbeat"
= I would take that fight.
If you guys haven't figured out that Jones won't be peer pressured into anything after UFC 151 then I don't have much hope for you but if you pay even a little bit of attention there is very little mystery here.