Giving a nation the idea you may support an enemy. Is in no way a protection from that nation taking control of your assets. It is at best giving the nation the ability to rationalise the need to limit your own power.
After all dispite not seeing any reason why any corp in the US would be worried about current potential govs nationalising them. It just not something either of the main parties are fans of.
Its even less likely musk would see cooperation with russia as a way to prevent such a thing.