actually it's not wrong
the new in new super mario bros is not there because the game is new, but because it's a new continuity ( seriously )
this series takes place after the mario universe reboot from the ending of mario galaxy
you know, the one where the koopalings aren't bowser's children anymore, just random minions.
rosalina did say the universe would be the same, but some things would be different, and that kind of thing is what it was referring to.
it was hard to name, they cant just call it super super mario bros, ultra/mega mario bros doesnt have the same effect, so they went for new. its the new super mario bros.
zelda a link between worlds was going to be called the new legend of zelda, but they gave up on that one unfortunately
if it meant more games like albtw i wouldn't mind.