It will, and it won't.

The thing that made Pac v. Mayweather bad was people expected a crazy war. Everyone spent that money going in and saying "this is going to be one of the greatest boxing matches ever!"...and it was boreing, so that was very disappointing.

The difference between that and this McGregor v. Mayweather fight is that, no one actually expects this fight to be good, they're going into it for the spectacle of watching one of these arrogant guys lose. If Floyd "Mayweather's" him like he's done to everyone else (which is expected most of all), every anti-conor person and boxing supporter will consider it great. If Conor manages to knock him out in 10 seconds, everyone will consider it great. If Floyd knocks Conor out in 4 rounds, everyone will consider it great.

I really don't think there's a way anyone considers it a bad fight, because no one's buying it taking it seriously, they're buying it just to watch the one they don't like lose...so either way it's the spectacle it was hyped to be.