Summoner isn't "endangered", just because the main Primals won't be a job specific spell doesn't mean the job is being dumbed down. Speculating at this point is silly, but more than likely Summoner, if it indeed is going to be an eventual class, will probably act like they did in XI and X where they will summon a pet and use their abilities in combat. There are SOOOO many summons in the Final Fantasy series and with artwork shown of Typhoon, Fenrir and Cait Sith, those could easily be great summon pets.

Plus the survey said a pet class (like summoner) so the Dev team has Summoner under a pet class category.