I think they can still attract good money even if GGG will lose to Murata since the fight is not just about GGG. Many fans also like to see Canelo and he will be the main reason why it will generate a big money. The anticipated GGG vs Canelo III is a much-awaited boxing scene regardless of what will be the result of their respective fight, GGG against Murata and Canelo against Bivol.
Do some people here really think that Murata will win against GGG? What if Murata won by Decision but it's clear that GGG is the winner? A Knock Out win is the only convincing method for people to see that Murata is a winner.
Then it will be a shame if we are going to witnessed a robbery if Murata is declared a winner even if GGG should be the one to win that fight. But let's see, I think GGG will try to finished the fight early and will go for the knock out so that there will be no home town decision advantage for Murata and not give any chance for the judges to change the outcome of the fight and derail his third fight with Alvarez.
We don't have to worry about that because it's more like an already an assurance that this fight will not be rigged as the Japanese people have been known around the world to be fair and square. I ain't really bothered that an instances like that will happen, but we will also watch closely to it because they're also human being meant to have a mistake.
Aside from that, Murata is really nothing compared to GGG. He doesn't have any advantage aside from his age and that he will fight in his own soil.
And speaking of robbery though, it seems that Murata has gotten the end of the stick as well:
https://www.badlefthook.com/2017/5/20/15669890/ryota-murata-robbed-as-fellow-japanese-standouts-take-home-wins
So we will see and hopefully it won't happen to GGG in Japan. We will never know though, we still have to wait and see if judges are going to be fair. So the only way to control the outcome is for GGG to score a sensational KO.