So another complicated things in this division and we might not see a unification after all with this boxing politics. Probably it's better for us boxing fans to see how Casimero will do in his maiden 122 lbs fight.
It would be one of the possible interesting matches of Casimero's 122 lbs adventure is a rematch against Zolani Tete. We all know that Casimero had KO'ed Tete in 3rd round of their fight and now Tete is somehow doing well in 122 lbs getting 2 KO victories and Won Commonwealth, IBF International, and vacant WBO International super bantamweight titles[1]
Also, in the world of boxing, Casimero is much more known and people already know what he can do while this Ryo Akaho is not that known yet because as you can see on his record, he's more like a local boxer but he made an appearance in this very industry once way back 2015 but returned to local fights right away because he was defeated badly by a Thailand boxer by a way of KO.
I think being popular does not mean they are a better boxer, look at Canelo and Bivol, Canelo is way more popular than Bivol and yet Bivol dominates their fight. So I think the better boxer isn't about how popular they are but how skilled they are. Popularity is more on the promoter's job by cherry-picking opponents and making their boxers look powerful.
So we don't know whether Akaho is not a match for Casimero until we have seen the conclusion of their match.
[1]
https://en.wikipedia.org/wiki/Zolani_Tete