That seems to be too tight. Assuming you get seated on time, it still takes about an hour to eat and get out, and that's assuming you don't have to sit and wait for any of the characters is some are slow at coming around. So let's say you get lucky, and get out at 7:30, you probably won't get to the Studios, and through security and the turnstiles until at least 8:00, and that's assuming a bus comes almost right away, and you don't get stuck waiting or have to make a bathroom break, etc. That gives you an hour, but by then, there's a high chance you wouldn't get seats. And that's with good timing for everything else.
Personally, I'd choose which is more important, dinner or Fantasmic. I wouldn't want to have to rush through dinner to rush to the Studios when there's a good chance it won't work anyway.