If CC has explained how colleges are selected for the “top univerisities” sub-forum grouping, I haven’t seen it. The “top universities” selection may primarily relate to popularity among CC posters and forum traffic, rather than eliteness or ranking on some website. Tulane received ~44k applications for the class of 2024, which was more than Harvard. With this many applicants, I would not be surprised, if it is a popular college among CC posters.
However, having a large number of applications and a low admit rate does not mean it is the same as another college that is thought of as “elite” by CC posters. If we want to determine how Tulane ranks or Tulane’s eliteness, we need to define how we are measuring those criteria. Any meaningful college ranking should explain what criteria they are using to do the ranking, so we can evaluate why Tulane is ranked at a particular number under whatever combination of arbitrary criteria the ranking is using.
What’s far more important is thinking about what you like/dislike about Tulane and whether it does well in the criteria that is important to you. An applicant who cannot explain why they like Tulane besides it being elite or ranked at a certain level is likely to be at a strong disadvantage in a holistic admission system. I interview students for a HYPSM school and regularly come across kids who cannot seem to articulate what they like about the school beyond it being a “good school.”