I understand importance of preservation, but frankly, the English WWW seem to massively and simultaneously overestimate rarity and undervalue financial costs of creative assets like 3D models and 2D images.
It's not rare that these assets cost in ranges of $10k and made in less than dozen man-hours each. They're not harvested and collected, but artificially created by individuals by work orders or as their own projects. A lot of these conversation feels like people are talking about something similar to Louvre collection items that cannot be obtained other than by somewhat illicit means, leading to discussions of which illicit means will be tolerated in the name of preservation.
No, it's something they make as we speak on Blender. Like with a mouse and a keyboard, or sometimes with a pen tablet. I think the anglosphere Internet hasn't yet reached the point where justification of dubious means can be discussed; we're at the phase where it should be educated to people more often that these are man-made creations that each has economic values.
I think you are missing the point here. The art assets in question belong to the studio. Yes, they are painstakingly made. They are made with the assistance of some very very expensive technologies. Full body scans. Facial rigging with 180 high fps cameras. Mocap suits and props in a full blown warehouse studio. The works. It's not just a 3D model. It's a rigged 3d digital twin of an actor. There's image rights, etc that have to be negotiated and deals made. Preservation would be to preserve the data as is rather than reworking it into a blender scene.