That will be so stupid it will fall flat.
the "I am your father" moment will happen when Luke tells Rey that she is his daughter.
What if it's a "You are my clone" moment when Luke tells her Palpatine grew her from his severed hand? Oh snap.
The Emperor is the father. Thats the big twist
Jar Jar will just rehash it and turn it into "I am your brother ... from another mother"
It will probably be a "we are your mother" lesbian parenting thing , I guess
Nah - han solo had a baby with luke. It's a gay thing. Luke used the force to make it all happen.