Yes, Main Street Bakery is open until park closing...well, actually, it's one of the places that is open after park closing some nights, along with the shops along Main Street. We stayed on Labor Day evening for Wishes...park officially closed at 10:00 P.M. Since it was so crowded with the masses leaving the park, we stopped at Main Street Bakery on the way out & had a snack. The place was packed - every table full, and long line at the bakery counter. This would have been at about 10:45, so about 45 minutes after the park officially "closed". Main Street was still quite crowded with people leaving (was over the initial crush at the end of the fireworks, but still a lot of people exiting the park.) Although there was still quite a few choices in the pastry counter, I did get the last cinnamon roll in the pan...and I heard the guy tell the people in line behind us that was all for the cinnamon rolls. there was a lot of muffins, turnovers, cookies & the cheesecake offerings were all there still. There were no sandwiches available that I could see.
Starring Rolls carries pastries for breakfast (also has some fresh fruit) but no breakfast sandwiches. They do have a limited supply of lunch sandwiches (all prepared in advance...good sandwiches but no special orders...you choose from the 3 kinds they have & that's it. Once the lunch sandwich supply is gone, it's gone for the day. Often are out of sandwiches by 1:30 or 2:00 p.m.) Starring Rolls does not usually stay open in the evening - have never actually seen it open in the evening at all. What I've been told by the counter help in there is that once the day's pastries are gone, they close. (they do not actually bake there ) Anyway, was told that they typically close by 4:00 or 5:00.
In Epcot, the Kringla Bakeri in Norway stays open in the evening...we've been in there on evening EMH at least an hour after Illuminations. They still had a good supply of pastries.