Are you looking for sophisticated or fun? Because I can't imagine any good reason to go to Whispering Canyon Cafe for an adult's birthday. Their food is really meh. Are we talking 21 year old adult? Or 55 year old adult?
Last year, my family went to Teppan Edo for my birthday (40s-ish adult). It was okay. No worse than going to Benihana for a birthday or anniversary. (Yes, I've done that before a few times). But you're not looking for theme park options..... I looks like there are some decent theme park dinner options.
Anyway, considering the limited options at the resorts, for a birthday for an adult, I'd look at Sanaa, Trattoria al Forno, the Wave, or Kona Cafe (I don't care what people say - the food and cocktails are good there).
At Disney Springs, Jaleo is amazing. I've never been to the Orlando Morimoto, but I've had a great experience at one of the other locations.