Unlike Juniel Querecuto, Fermin is still very young and should have no problem finding an organization that wants to have him around as organizational depth. As for the Cardinals, I just see too many names in front of him for them to bring him back.
Masyn Winn, Nolan Gorman, Brendan Donovan, Tommy Edman, and Richie Palacios would all get reps at shortstop and second base ahead of Fermin, and the emergence of Thomas Saggese means there's another player needing significant playing time who is knocking on the door of the big leagues. While they could still keep him around as insurance, they also have names like Irving Lopez, Nick Dunn, and Kramer Robertson who can provide that.
Fermin just has not done enough at the big league level this year to warrant consideration again. He slashed .235/.339/.255 on the season with 0 HR and 4 RBI, and while he's a capable defender, he's not special enough to fight for playing time with the names above. I do expect him to find a role elsewhere though.