That's an interesting question to think about.
If you mean the original Diane seeing how the new Diane (Jason) looks, I'm not sure if that would make her want to be a woman again, or go back to her old body. I guess it depends on how those male hormones have changed the original Diane. Back on pages 496-498, the original Diane was flirting with that female bartender, and we learned that two previous attempts to flirt with women have failed. So, the original Diane is now interested in women to some degree. I don't know if she has lost all of her original sexual orientation or if she is like Jason (the new Diane), who is still occasionally lusting after people he shouldn't be (as a straight female character). I would be curious to see what kind of porn the original Diane is currently watching.
Ya know... for some story insight.
Now if I misunderstood and you meant the new Diane (Jason) seeing his old body that the original Diane is currently in possession of, that should be quite dramatic.
I could see that situation going in many different possible directions.