The monorail cabs have an air horn similar to a boat's fog horn. It is loud, but I don't know if it would have been useful.
Pink's pilot was in the lead cab as it drove forward to pylon 30. the track was to switch. Then, he would have been on the pusher end until he reaches the switch for the maintenance barn. This means that he has only mirror view through TTC, Poly, GF, and MK. The mirrors are not that big, and would have had no view of the TTC from the curve of the Epcot or transfer beam.
While multiple humans were involved, this can't be blamed on a single person, but rather a series of failures. Any one of which, had it been changed, would have prevented this.
The current revision of the monorail system is technologically dated. I agree that multiple cameras will likely be added, as well as a second pilot for all instances of a monorail reversal of direction. Also, there will most certainly be a human at each track switch to verify the position.
I can guarantee though, that, as a corporation, Disney is already working on the solution, and will not wait for NTSB's final report.