I imagine that Palpatine planned on making it so. The Sith are strange to me. They are so evil, so greedy that they consume themselves. Palpatine was determined to get an apprentice much stronger than himself, in either Luke or Anakin. Had Palpatine got his way, I don't see him lasting long with the handsome, popular and most importantly, more powerful Skywalker (Luke/Anakin) at his side. He would almost certainly have been killed a couple of years after turning them with a new Skywalker as emperor.