I was there for NYE this year, and they were allowing people to wait, however we had a FP for it (I think then you could only get a "FP" for it, individual of your ride FPs, on a separate Disney site. Long and confusing, now gone since they are ADRs). The CM at the front told us the wait for walk-ups was over 2 hours.
This past May-June, they were turning away any people who were walking up without them. We ate there 3x, and for dinner the man actually got very angry at me because his coworker wrote she gave me beeper, say, 62 but I really had 63 (they were one number off), and he didn't believe that it was really me with the reservation even after I showed him my ID! He had to "confirm" with multiple people it was me and spent a good 20 minutes running around the restaurant...despite seeing my photo drivers license and me having a not-at-all common name, my photo ID, and several credit cards with my name on them, AND the confirmation that I showed him in the
MDE app! A family next to us was furious because the mother said she was waiting over 45 minutes for the same reason, and it was pouring outside.
However I digress. The point of me telling that story was that even with an ADR they were extremely careful to make sure they were letting the right people in, and shutting down all walk-ups, so the moral of the story is it can't hurt to try to walk-up, but keep checking!