On top of Dribble's comments, I'd remind that he is young and a lifelong rojiblanco - some may point to him being deemed surplus a couple of years ago but this happens often at Spanish clubs, rarely does it result in lifelong division. If anything, it reinforces the desire to eventually return & thrive at your boyhood club. Plus, the player himself while surely a fan of Pep & Busquets, is a big fan of both Gabi & Simeone - legends of Atletico. I don't think it is a simple choice for a player of his ilk to make, surely if Cerezo wasn't even considering to improve his wages the choice would be easier but all things being equal is a different story.
I wouldn't read too much into how quietly this possible transfer is moving either. Moreover, Txiki et al are surely on top of things and if the player gave the impression he was either unsure of a move or waffling, the club would react accordingly rather than be left with no alternatives should it not work out in the end