Not exactly. If you want an updated view of the R=U theory, go to:

www.gamefaqs.com

Find Final Fantasy 8 --> FAQs and Guides --> Time/Ultimecia Plot FAQ.
Oh, and here can be two "yous" in a place at once in FF8. This is proven b the fact that a young chuld Squall stands next to the Squall we play in the scene at the Orphanage in the ending.