It's their property, they don't owe it to anybody. There's nothing sketchy about this.
It's likely that they always intended to release CAD models, but it took time to clean them all up and get them in order. Usually you don't want to make a public release with your original working files because they're messy and would cause more confusion in your user community than benefits.
Ownership in general isn't some fundamental inalienable right. It's just that if you let people own things, you give them more incentive to make things. I think intellectual property rights are far too extensive, but if we didn't have them at all, how would we pay for R&D? How would we pay for big budget games and movies? Maybe you're happy contributing to openly licensed projects, but a lot of people have to pay for rent and raise a family, and can't take the time to contribute to things like that even if they want to unless they have the money to support themselves.
And how do you get people to collaborate? People have tried making governments based on the idea of everyone working together for the common good. It never ends well.