It's just a rumor everyone. Saga actually mentions in some of his interviews that he's a pretty lonely man. What can be confirmed is that Saga does like girls from overseas.
Yes, it's just a rumor. btw, the bunny girl in the Blue Planet PV is not Reina. Tora mentioned that her name is CHELSEA in Neo genesis Vol.25. They are not even the same person. Too many people misunderstand about that.... And about a rumor I found this link
well Saga did say in an interview that he hoped to make his parents grandparents some day(something like that) but that really doesn't confirm anything.