Was there a couple weeks ago ...
Restaurant and
Lounge can be booked in advance via ADR.
Restaurant can be booked day of if you get in line at restaurant before opening. They will give out reservations until none are left. We were about 4th in line and got 2 pm. Couple in front of us got opening. Group of 7 in front of us got afternoon sometime. (Our plan was lunch only, if he offered dinner we would pass).
Lounge can not be gotten day of, I assume since that books out fully no need.
BAR you can wait in line for, that is bar seating only first come first serve, one party in, one party out depending on numbers.
Obviously any given day there might be some variation but they said that is how they are handling it now and it's working. My opinion was restaurant was mostly full and lounge was full. My assumption is if someone cancels a Lounge it goes back into the Disney
MDE system. This also makes it a non-discussion issue for CM at restaurant.