I'm glad that Kalisto is getting called up. He's never had too much entanglement in NXT stories, despite getting a title run, and I feel like he's about as ready to plug into the role they want him to as he's going to get. Their run with the NXT Tag Team Titles has come to an end, and it's time for them to do their plucky babyface shtick on the main roster.
Don't jam Kalisto down our throats as a major player out the gate. He's an incredible athlete trying to find his feet on the world stage. When Rey Mysterio debuted he got featured, sure, but he did his fair share of Velocity work as well. Let eyes go to him organically, and when he is ready to get a solo spotlight, have a bad guy take out Sin Cara and have Kalisto take up arms for his first singles feud.
It'd make sense to put them against The Ascension eventually, but I think The Prime Time Players are first in-line there. The Lucha Dragons can have a respectful feud with Los Matadores, which becomes frustrating for Diego y Fernando when they can't get one over the new team on the scene, and they turn heel to intensify things. See if bad bullfighters can get over better than good ones.