Removing the Russian segment from the ISS isn't feasible, as it has the only module capable of GNC, and Progress is the only currently flying craft that can raise the ISS's orbit (which, being in LEO, slowly decays).
Russians also can't remove Zarya anyway because they don't own it. The US purchased the module decades ago when Russians had no money. (They still have no money, but they used to have no money, too.)