Even if he knocks out Saul Sanchez, I do not think that Inoue will be interested on him anymore. Naoya even skip Murodjon Akhmadaliev, a much tougher opponent than Inoue if I'm not mistaken.
Naoya just wanted a easy last fight at super bantamweight that's why he chooses TJ as his last. So even Casimero wins, Inoue will move up in weight class. It will be good for this contender though as all the belts are going to be open and maybe for the last time, Casimero will become a champion at super bantamweight.
Boxing fans will be intrigued and there will be hanging questions about what will be the outcome if the fight between Casimero and Inoue materializes, so it will just fuel the discussion between the two, Casimero is pressured to win this fight and he must win it dramatically like knocking him out in the early rounds.
Because he's been bragging that he can beat and knock out Inoue, he will end up a laughing stock if he has a hard time against Saul who is considered not on his level.
If Inoue leaves the Super Welterweight and Casimero has a good showing in this fight he might end up ruling this division, so the discussion between the two will continue if this scenario happens.