I don't think it's likely that Ukraine will join NATO. I think there are European members of NATO who will make sure that doesn't happen.
As I said, Russia is not prepared to abide Ukraine in NATO. Ukraine is not comparable, from Russia's point of view, to Poland or the Baltic states. Sebastopol and Crimea are not in Poland or the Baltic states. They are part of Ukraine. Ukraine and Russia have a shared history of a thousand years. It's chalk and cheese between Poland and the Baltic states, on the one hand, and Ukraine, on the other.
I don't think that Ukraine would be ready to join NATO, given NATO's qualifications and conditions that there not be disputes on the territory of its members. I think there are members of NATO who do understand that it's a provocation that would be counterproductive.