If there was a will for it in the EFL heirarchy, they'd probably have to say if they don't accept 3 up 3 down they'd cut the promotion places down to 3 out of league 2. I think one of the issues we have at the moment is that clubs coming up in recent years have really small attendances. There is no guarantee that if they made it 3 up, 3 down that the bigger teams will go up. Just look at the seasons we've been down here. Sutton, Barrow, Harrogate and Hartlepool have gone up. Hartlepool are the biggest of those 4 but hardly have massive attendances and don't really travel with lots of fans.
To get the turkeys to vote for Christmas, you're going to have to sell them something that they will benefit from and that is either take away the easier jump to league 1 or try and convince them of bigger gates (but that potentially comes as bigger competition!)