We really wanted to try this place, but no luck so far. Too much trouble to make the trip and chance not having walk up ability.
I continue to be amazed that Disney wants me to make a reservation to eat ice cream. Uh NO!
The OP is correct that you don't need a reservation to get ice cream - just enter the door on the right and you will be helped. And on a couple of occasions we asked for seats at the fountain bar, without a reservation, and we got them.
I thought I read somewhere in here that it changed. Only a small window of add for lunch and the rest walk up?
You don't need an ADR to eat ice cream. You can walk up. If you want to eat a meal there, you needed an ADR in the past.