How do you know he's not had an offer from a Championship team?
He might well have had an offer from every single team in world football in January, but turned them all down to focus on his football til the end of the season, when things will be much clearer for him. I mean, for example, if he had signed a pre-contract with a side like Everton he would already be doubting his future there with the managerial changes and relegation prospects. Had Gio been here a few months longer he might have chose to leave then regretted it when Beale came in. It would be a bit mental to make a decision now when he knows he'll get all the same offers, with more clarity, come the end of the season. Plus this way he doesn't upset the fans he's abandoning (til he actually leaves) and can focus purely on his football.