The Twins should not move Gray unless the return is greater than the sandwich pick they will receive after he rejects their QO at the end of season.
If they want to package Gray with someone like Larnach to add to a deal, sure. Maybe someone wants a veteran bat like Solano, so he could be in the mix if Polanco's return is imminent.
Maeda has been pitching very well since his return, but since he is a pending FA they could deal him, but that would certainly hurt their prospects for the balance of the year.