I don't think the Conor can bring something different that Mayweather hadn't seen before. From Pacquiao to Marcos Maidana to Jose Luis Castillo. So it doesn't make any difference at all. And even he can rough up Floyd at the beginning, he will just simply adjust as what we have seen Mayweather throughout his career.
Let's say the 'puncher's chance' comes in. The lightweight champion instantly becomes the the biggest athlete on the planet, crushing the sport of boxing in the process.
Mayweather has seen everything when it comes to professional boxers and no one could defeat him, on the other hand McGregor is not a professional boxer and he does not move like a boxer and has a crazy style and these are the things that might surprise Mayweather, another factor is the age,he is the best defensive fighter because he is seeing everything and making decisions pretty fast now his age is the most important thing ,with age your reflexes reduce and lets see ,i am interested to see how this fight ends.
The public believe this will be the fight for Mayweather, you can already tell based on the betting odds but other than that they also expect it would be an entertaining fight due to the fact that McGregor is an entertaining fighter. If the game is dictated by Mayweather, there is a less chance we can see an entertaining fight as he is known to be a boring fighter but I don't really understand why they keep criticizing him after the fight but should support in buying subscriptions and tickets to watch the game.