After digging into it, it seems like the 2 week limit was a bug that has been fixed by steam. So there is no Steam enforced limit, it’s up to each game’s DRM to enforce restrictions. Steam can function as DRM with a simple command during upload, but it’s rather basic and Valve recommends publishers to use additional DRM for more serious protection.
GOG on the other hand is DRM free as a core policy so you’re guaranteed no restrictions.