My guess is charging for the monorail might have been discussed, but I just can't see them doing it. Riding the monorail has been free for decades. The protests would be deafening, not to mention all the bad press.
Families wanting to take a break with their kids in the afternoon would now have to pay extra for the privilege to do it. Guests without cars would be penalized for wanting to travel from the Transportation Hub by monorail to EPCOT. The shuttles would be free, Magical Express would be free but not the monorail?
I just don't think there's enough pixie dust to make this one fly.