This fight may eventually happen because some of the prominent names in Philippine boxing are losing one by one, the one remaining now is Mark Magsayo but Magsayo is not Manny Pacquiao and he is in a division that is loaded with great boxers like Navarette, Lopez and Joe Cordina this is a tough time for Filipino boxers, there was a time that there were 5 Filipino World Champions, now there is none.
But I not sure that their fight will actually be held soon because Inoue himself will probably move up division to be able to get more titles in different division, it just that Casimero is more likely to really want to be able to face Inoue.
Moreover, Inoue has succeeded in getting 4 main belt titles in the two classes he has managed to master, when he faces Casimero he will not get anything more valuable and when he loses he will only feel regret.
Previously there had been many rumors circulating about their fight but Inoue seemed to be avoiding this fight.
Currently, Filipino boxers are really can't be expected, in the sense that no one can be seen as really strong and able to win more championship titles like Manny Pacquiao who was able to take seven belts from each different class.
Maybe there will never be another Filipino boxer like him.