^^ I think both has pressure to win their fights, so that this mega fight will happen eventually. So if either one of them losses, as you and the other posters have said, the hype will go down a bit.
So its very important to hurdle their fight first, GGG against Murata in Japan, and then Canelo against the reigning LHW champion on Bivol.
And I agree that Canelo will be the A-side in this fight, maybe 70-30 in favor of him.
As far as I can see, even Canelo and GGG will lose their upcoming fight, the impact and excitement is still there when they faced for a third time. It's a fight that everyone anticipated to happen for a long. To settle everything and it seems it's now likely happening, a third match is necessary to negotiate.
Just seems concerned to GGG here how he can deal with the prime Canelo if he will lose to Murata that is not even in his league.
About the split, 70-30 split is too much. Canelo is too overrated if that will be the final split.