Not so sure, the majority of players would rather get paid in their 20s, only a few stay healthy and perform well enough to get a big FA payoff, and those players and the top agents get the benefit, but the majority of players and agents would benefit from more money in the early years.
So I could see raising the minimum wage, raising minor league salaries and a minimum floor on team spending. Maybe allow team to "hoard" cap room by moving it forward like the NFL.
Teams would fight moving up FA tooth and nail, and it would slash expenditures on player development, why invest in player development when it doesn't provide a competitive edge? Just when players become productive (2-3 years into their career) you'd have to pay them as free agents. So either you end development, or stash players in the minors an extra year or two to ensure they're immediately productive.