I definitely think capacity wise it would work but would it be that much cheaper? You have to build new stations and then retro fit the resorts since they are built around the monorail. You’d have to redesign the TTC, inside of the contemporary and demolish stations at the poly and grand.
As far as I’m aware the beams are still suitable for now so Disney really only needs new trains.
I think it would depend on how daily operations costs stack up. Everything points to gondolas being much cheaper to operate. Write off the expense and make the change.
For those concerned about a gondola fitting into the CR's openings keep in mind that you can take out the monorails beams.