I strongly suggest getting reservations for any sit down in WDW.
When we were last at Tokyo Dining, walk ups were being told they’d have a minimum 45 minute wait.
Bella, I think they’ve kept the sushi bar going at the Poly, at first it was just an experiment. It’s a split operation. In the morning until mid afternoon, it’s a coffee bar. Somewhere around dinner time, they reopen as a sushi bar, but their menu is pretty limited.