Weird?

I'm pretty sure Kirk and Agnes also can't eat there.

It makes sense that Luann, Agnes, and Krabappel don't eat there since they are the owners. They want to bask in the glory of the new business, "sit back and watch the money roll in like it exploded out of a giant floating thumbs up." Luann probably wouldn't want Kirk eating there. Doubt he could afford it anyways. My guess is that Suzanne, Boobarella, and Kodos not being able to participate is an oversight by EA. They probably just failed to update the characters to be able to partake since they were added with the Hallow's Eve update.

^^^ this is exactly why, and kang can eat there cos he was added last year