This is a good point, but the idea of “a good strategy is to stay small” applies to almost all elite colleges AND universities in the US. Many elite universities could expand but choose not to, not because of limited resources, but it is hypothesized, to maintain the brand and exclusivity (like Rolex, or Hermes).
Why don’t elite universities expand? Great podcast on this from Freakonomics: The University of Impossible-to-Get-Into (Update) - Freakonomics