This was a good episode. It wasn't bad nor average like the past couple of episodes in the last couple of seasons but it's not a hidden gem and it wasn't that exceptional.
It touched my heart a little bit and the lesson was nice.
I liked the plot with Bart and the teacher more than the B plot (The octopus and Lisa) which was kind of boring, but not that bad.
It's kind of sad that they're replacing Krabappel after all these years, but what are you gonna do, they killed her off because the voice actor sadly passed away.
I don't really understand why some people said this episode sucked, it wasn't bad.