It would have no effect at all. Public universities are part of the (state) government, so are bound by the first amendment. Open source projects are not part

It would have no effect at all. Public universities are part of the (state) government, so are bound by the first amendment. Open source projects are not part of the government, so their freedom to associate with whoever they choose (with some limitations implied by eg the 14th amendment, but nothing likely to affect currently prominent codes of conduct) is protected by the 1st amendment.