This will never happen, anyway. These are teenagers and, mostly, kids in their early 20's. I'm sure their thinking is, "give it a try, if it doesn't work, I've got lots of time to move on to something else".
Also I expect MiLB is treated as a separate business venture from MLB, and the financial considerations are separate. And the revenue in MiLB is relative peanuts. The recent downsizing of MiLB was likely based on financial considerations - improve margins, reduce number of teams operating at a loss or breaking even. All this is just to say, there is little rationale for increasing MiLB player payroll.