Amazon or Apple or whatever streaming platform would give them the most money, and then the remaining games are sold to ESPN in a package for both linear programming and ESPN+.
The PAC-12 could tout the ability for all those ESPN games to potentially be on linear programming though ESPN has the flexibility to put most of them on streaming as well. Maybe they get a guarantee of at least 2 games per week on ABC/ESPN/ESPN2, with the other 2 games per week on Linear or streaming at ESPN's discretion (though I'd imagine the majority of those would be ESPN+). Is that close enough to 50% to make the presidents happy?