Connor Mcgregor is such a famous name that he is already breaking the gate record and there are months before the fight, so imagine how much money his return will make. I am not sure how he is going to train because for the movie roadhouse he did looked a little buffed up and a lot of people questioned "how" that happened, but I am sure that he will end up training properly like he did back in the day and get back in shape and weight and hopefully it will do fine.
I personally believe that at this age, with this much break, he is not going to have much advantage, but that still doesn't change the fact that he is one of the most famous fighters of all time and he will be a great marketing for duelbits without a doubt.
First of all dont trust everything you see in movies
Secondly about his shape - he is huge because he was on steroids. The reason why he used them - some say because it helps to recover from injury faster. Thirdly about his weight - he wont be able to fit in lightweight anymore, so probably a catchweight. Fourthly about his chances to win - I would say they are extremely low, as he has lost motivation long time ago. He went MMA because he needed money. Now he is rich, famous. Why should he kill himself training and allow other to punch him in the face?
Biggest money maker for UFC and highest paid MMA fighter ever, most expensive debut actor, most expensive debut boxer, most expensive crypto casino promotor ?