The fact that they won't just freeze uploads and leave it up is just stupid.
People always bring up "What about maintenance costs in terms of dev time!", but at the core this is literally static assets. No fancy API, no crazy isomorphic app or something needing fat servers.
Just 3D modeling files.
Literally they could generate a static page for each asset that uses the preview image instead of the 3d viewer, stick it in their cloud storage solution, and have it exist, untouched, in perpetuity.
The cost wouldn't even register on a microscopic scale for a place like Google