When Mrs. Peyton introduces the other teachers Lunch lady Doris looks at the Buzz Cola machine and then looks at Mrs. Peyton, Then the scene changes to close up Lunch Lady Doris did have a phone in her hand, also her eyes are wonky and when the teachers left the lounge her phone disappears.
Since Mrs. Peyton became Bart's new teacher, it's never explained what happened to Ned Flanders who became his teacher in season 29.