Yes as in he will improve and stay qb?
Yes he will stay at QB as long as Arians is the coach of the Cards.
a. Arians likes his TE's to be blockers.
b. Arians likes vertical passing big QB's which Thomas is with some athletic ability.
c. Arians likes building guys from scrach, look at Big Ben.
Besides Logan is a more natural QB than Cam was. He actually understand pro plays and goes through progressions. He just needs to work on his technique, his feel for the game, and his footwork. Those can all be fixable. He will never be a 100 QB rating QB. He's a vertical passing type like Flacco and Big Ben. His job is to pass the ball in the intermediate and deep balls at a good rate, extend plays, and be tough.
He doesn't need to have the nuisance of the game for his style of QB.