What I'm opposing here isn't that ordinary Russians are prevented from having their voice be heard but RT which is financed by Putin is somehow allowed to continue posting. If the playing field would be level then they would also be prevented from posting until they restore access to the rest of Russians citizens.
Would that be a fair compromise? What else is there that twitter can do to not have blood on their hands by enabling such an asymmetry? (keep in mind that information pushed into these networks is also seen by combatants and will shape morale, so the argument that twitter is somehow neutral is hard to justify)