This is not accurate. Here's info for the University of Michigan for example. Ticket sales are almost exactly 25% of revenue. https://twitter.com/darrenrovell/status/1250500598589460487
You can click on any school's name in this @ByBerkowitz database and see the breakdowns: https://sports.usatoday.com/ncaa/finances/
Example: 30% of revenue for Texas comes from ticket sales. https://sports.usatoday.com/ncaa/finances/