If they would see soo much demand with Casimero vs Inoue then he might consider on pushing it to happen but lets take this a pinch of salt because we dont know
on whats up to their minds.
Casimero is already popular, so I believe they already know that the demand for the fight is high, however, the promoter is also looking about the possibility of the outcome of the fight, if Inoue would lose in the fight, that would be the end of his future and Bob Arum would not be able to earn from his investment on Inoue.
The problem with this division is that there are no US names, maybe except Donaire who have been campaigning for many years in this division, but I do think that Inoue and Casimero is not yet a household name, they are just starting to build one in the US soil. So both of there promoters, specially Inoue, should established their names first, create more hype so that US fans will buy their tickets and make more money for Bob, just like what he did to the career of Manny Pacquiao.
Manny Pacquiao's journey in sports is very exceptional, he is undoubtedly better than Inoue, he fights anyone and beats them. I never remember anyone who challenges him that he did not fight, he is humble in personal but a beast in the ring. Casimero is a champion, Inoue should unify with him if he is confident that he can beat Casimero, if not, there will be a lot of excuses and it's easy to use the words "it depends on my promoter".
Looks like Bob Arum wants to save the fight against Casimero as Inoue's last fight, and before that, he would make Inoue fight a fighter that he knows he can easily beat while people are still urging Inoue to fight Casimero. I don't know, there's no pride in boxing anymore, it's not the fans tha are followed, it's the promoters will to make more money and make their asset a cash cow.