If the installer is open source, then that part is open source. It’s maybe not as useful, because it relies on proprietary software to work. On the other hand, so does emulators like Dolphin.
Windows is not open source just because it’s possible to change dll files. Minecraft is not open source just because it’s possible to modify its textures.
Model weights isn’t the equivalent to a proprietary DLL or GameCube ROM. Anyone is free to modify and distribute the model weights however they like - and people are already doing it. Soon enough we will see variations of the model without the Chinese censor for example.
The model is as far as I know open, even for commercial use. This is in stark contrast with Meta’s models, which have (or had?) a bespoke community license restricting commercial use.
Or is there anything that can’t be done with the DeepSeek model that I’m unaware of?