Not sure winning teams matter for MVP as much as you think but even so not like Freddie is on the Pirates. Braves are going to win their admittedly crap division and be the 2 or 3 seed in NL. And they’ve had literally one reliable SP all season.
Their offense has carried them and Freddie has been a huge reason why. His numbers are outstanding. And don’t forget he had legit Covid with 104 fever in spring training and barely got back in time to start season, and struggled out of the gate. That could persuade a sympathy vote or two as well.
He’s also beloved by everyone so don’t discount the lifetime achievement award factor.