I have to wonder how much the Mayweather/McGredor fight is going to take away from this fight.
You know, a lot of people are dumping on Mayweather for trying to steal the thunder of the Cotto vs Kamegai fight, and the Golovkin vs Alvarez fight (among others, probably). I really think Mayweather did this to try and prove something for his ego - namely that he still wants to feel relevant. He hates other people getting the spotlight so he tries to dampen them out. He picked a date when Cotto was fighting to spite him, and he picked a venue where Golovkin and Alvarez are fighting to spite them. These examples demonstrate him to be a man that really doesn't care about anyone but himself, and while there are countless people that will say, "who cares, he can do what he wants," there are countless others that would say that if you're such a big fan of him you really ought to realize that you are supporting a guy that is just trying to snub out the development of the sport that you love. And, to be perfectly honest, you wouldn't know who he is, if not for the sport. Yes, it's his prerogative, but then you have Muhammad Ali, who is beloved by all, not hatefully remembered, and that's because he had a different prerogative: people. So there's that.
Thing is, the boxing fans are gonna watch those actual boxing fights and they are gonna find the news and media they want for them. Simple as that. Radio channels that were broadcasting about how Mayweather vs McGregor was finally signed weren't already giving out all this boxing news already. They caught wind of the freakshow and it's out there. It's not like, for the most part, boxing fans are going to flock over to the Mayweather vs McGregor fight because most know that it's a dumb sideshow that's really just a veiled excuse for millionaires to make millions more.
In the Venn Diagram of fans, there really isn't much overlap: casuals and MMA fans on one side, boxing fans on the other. There might be some overlap in the middle, but it will be negligible. I really don't think he gets in the way of the boxing fights (other than Cotto vs Kamegai, which really just seems like a punitive act on his part).
Is Mayweather a great fighter? No doubt. But for a fighter that cares about legacy, he won't be near the hearts of so many fans once the sands of time wash over his memory, he'll just be defended by the people that like undefeated records (and this is, obviously, because he is a very effective fighter, so they'll like that too). But Marciano had an undefeated record and nobody hates him (wait, Larry Holmes might, right? lol). Mayweather may be a decent human being if you meet him (truly, maybe even a bleeding heart orphanage owner, for all I know), but he sure isn't showing much love for the sport that gave him all the opportunity that he has, and people will remember him for that. I expect some to say, "uh-uh," but also, I'll be right. He won't ruing big fights like GGG vs Canelo, and he won't enhance his reputation/image/legacy by beating a gut that (according to recent reports by the BBC) didn't even have ONE amateur fight.