SE, don't overthink Summoner 7.0. Just give people what they want. Just do it.

[Whalaqee]

What is the sense of adding elementals after phoenix?

Fleshing out a job fantasy of being a summoner from a thematic and mechanical standpoint. Likewise the same for Demis that could add even more primals. Or new traits that modify existing abilities like fester or aetherflow or physik to give them a more primal feel.