I feel like Jubilee looking down on the teens added later is just a retread of the 'Kitty calls the New Mutants 'X-Babies' and flips out childishly when re-assigned to join them.' It was a cutely ironic move back in the day, but clearly was done tongue-in-cheek, and not to make Kitty look great, and I'm not thrilled to see it recycled, either with Jubilee and the New X-Men, or various New X-Men looking down on even newer arrivals, or whatever. (Counter-examples, like Julian and Santos hanging out with newer-creation Broo as 'X-bros', are nice contrasts to that.)
There's a part of me that wants the generations like the New X-Men who 'showed up together' to stick together (since I love their various interactions, like the initially icy relationship between Surge and Dust, or the romance between Hellion and Wind-Dancer), but another that fully supports some intermingling, so that we can have groupings that include some 'classic' New X-Men and some others who arrived at different times, like Goldballz or Nature Girl or Shark Girl or Armor or Evan/Genesis or Ernst or Teenage Negasonic Warhead.