Harry Potter was a "new kid in school" plot. The difference was it wasn't about being the new kid in school as much as it was about Harry Potter. (I don't even think the magic was the important stuff. It just made it different.) Now everyone wants to do Harry Potter with some minor twist or different magic. In that case, yes, it's cliched!
"New kid in school" isn't different. It's who the new kid is and that the story isn't just presented that it turns out to be new kid meets people and stops being new kid by the end of the school year. Gee, no kidding. How else would it turn out? There's no plot in that. Also, when the first thing that happens is the new kid goes into school feeling all small, insignificant and new, and then goes to the first class just to see the teacher and other kids in the class... I'm sorry, but why do I read such a story? That's like reading algebra homework for fun. I have to do that every day, so it's not escaping from real life.
And then there is a vampire cult in the school? For the amount of vampire stories available to me, it might as well be a cult of cheerleaders. At least that's different. I'm beginning to believe every school has vampires.
Or, how about new kid in school is really the son of a famous wizard/god/demigod/vampire hunter/vampire/or is, unbeknownst to him, a superhero in hiding? I think there are less cheerleaders in my school than books of that nature.
Or wait! How about new girl in school wanting to date bad-boy. What's wrong with normal boys? Do we offend? What possible good can come out of dating a bad-boy?
I just read a book about a gorilla stuck in captivity from the gorilla's POV. Now that's different. I just read a book about a boy dying of cancer. He died! Now that's different. I read a book about cowboys in North Philly. I didn't even know there were cowboys in Philly and I live here.
Nothing inherently wrong with writing the same stuff in different ways. Just make sure it's "in different ways." After all, Harry Potter was a new boy in school. That was different. It's no longer all that different, but it was different in its day. :D