Four resorts? The only resorts on the monorail loop are Contempo, GF, and Poly. FW & WL already use buses along with water taxis. In addition, GF and Poly also have water taxi docks. So the only place buses would be an absolute necessity would be Contempo, but then only for those unable or unwilling to walk the very short distance to MK. Transportation from the resorts to parks other than MK is already done by bus.
Not to say they wouldn't add buses, but those buses wouldn't be shouldering the entire load of getting every monorail resort guest to MK. I just don't think it would be the "cluster" you or the government think it would.
Bay Lake is the 4th resort. And the boats for GF/Poly are small.
You seem to forget that the monorail resorts don't have buses going to Epcot.