Try to extrapolate on Kosovo but then take into account that there was no vote on the fate of Kosovo. The Christian population was killed off or chased away by NATO.
Russian soldiers didn’t vote in the Crimean referendum, that’s just Ukrainian propaganda.
Check out reputable pollsters on the issue. The approval of the Russian administration of Crimea improves every year. They remember the years of the Ukrainian control as hell on Earth.
So if Poland invades and annexes the Oblast and then holds elections whose results show a clear majority wanting to join Poland you’ll respect this, right?