Think bigger picture and longer term. Any conference can increase the amount they charge for broadcast rights for all their schools (and every school in any conference can raise the prices of tickets, concessions, and memorabilia, logo wear, etc.) to offset donations that go directly to players and not to the schools.
For the non-revenue sports, there will be ways to get scholarships funded. Speedo could become the Official Sponsor of the B1G Conference Swim teams, with all the proceeds going toward swimmers scholarships. Nobody has to be left out of the windfall that will come from sponsorship fees.
I’m sure there are hundreds of other ways that this NIL thing can evolve into funding for every athletic scholarship and non-athletic ones as well. The outcome you’re imagining doesn’t have to be the only one.