Pretty simple. The WBA making Cotto Super Champion frees up his regular belt for other contenders to fight for=more sanctioning fees. And Saul Alvarez's bro is not the regular champ, he's the Interim champ, which is yet another WBA belt! The WBA are the biggest joke going around. If you look through their champions, they have atleast 2 champs in virtually every division. They have three each at middleweight and featherweight. The Ring and other boxing publications have got to stop recognising these clowns.
Because the WBA is sh#t! If there's a boxer who holds another title, or has a big name they promote him to Super Duper Ninja Turbo Champion so they can have another regular belt. They do everthing to hold control over their titles, so they can jack around with their ratings/contenders as much as they like and get as much sanctioning fees and bribe money as humanly possible.