While this is an awesome sounding story, there are a few reasons why I think this plot is made up;
1) I doubt that lucas film would create a brand new trilogy with the puppet master once again being Sidious. While it would be awesome to see the residual effects Sidious had on the galaxy, I don't think they would just straight up bring his character back.
2) Star wars is primarily a family drama. However, I am beginning to doubt that Rey is Lukes daughter. Unless Luke somehow used the force to create her, they would need to introduce a love interest for Luke, and I think that Luke is of the traditional Jedi mindset that love and relationships should not interfere with their responsibilities.
3) I would love to see some Sith presence in the storyline, and furthermore, I would love to see Benicio del Toro portray that character. I just doubt that they would embue Snoke with the power and majesty that they did in the Force Awakens only to strip him of it in the next installment.
There are plenty of plot points in this leak that seem plausible, but I don't think that this is how they will be arranged. Just my thoughts.