The original Title IX law never mentioned sports, but guidelines have been issued since that have included topics such as sports, sexual assault, LBGT protections,... Part of the reason there is confusion over Title IX and sports is that there was an amendment that was proposed to exempt revenue generating sports from Title IX which did not pass in 1974 called the Tower Amendment. And, there have been other attempts to exempt revenue sports from Title IX as well, but none have passed.
In 1984, the Supreme Court ruled that Title IX did not apply to sports, but in 1987, the Civil Rights Restoration Act of 1987 overturned the 1984 Supreme Court decision.
There have been many guidelines and rulings since. Bottom line, anybody who says they will just exempt revenue producing sports from Title IX doesn't understand the history. And, I think NIL is different than revenue sharing, but maybe a court will rule that revenue sharing is NIL and those revenues should be allocated based on revenue production.