I don't think you understand how University endowment funds work. To put it short they diversify into asset classes - one being top tier VC (Sequoia, a16z, USV, etc.).
In other words, endowment funds are investors in virtually every type of company possible - public entities, lending, credit, cash, hedge funds, startups, etc. - they simply don't care what the vehicle is as long as it meets their risk adjusted return goals.
Depends on the university. Stanford got much more aggressive with investments in the 1990s. They spun off the endowment as the Stanford Management Company, headquarters on Sand Hill Road out by the VCs. They did very well - part ownership of Google, Cisco, Yahoo, etc. 12.2% average return per year over 30 years. It was starting to look like SMC was the tail that wagged the dog - a VC fund that ran a school as a side project for the tax break. They had their own CEO.
So they were pulled back to the main campus, made a department of the university, and made somewhat less independent.
In other words, endowment funds are investors in virtually every type of company possible - public entities, lending, credit, cash, hedge funds, startups, etc. - they simply don't care what the vehicle is as long as it meets their risk adjusted return goals.