Right. And he can actually train for that this winter, instead of worrying about mechanics. Muscle Memory helps you be more loose, and it can result in an increase in velo as well.
I also noticed with Gio this year that if he was really cruising in a game he threw harder. The more confident he is in a given start, the harder he throws.
You may be right about his velocity being what it is, and it's more than fine where it is. I just wouldn't be surprised if he had a 0.5-1.3 mph increase next year, just due to muscle memory and training.