Disney won’t be having bus drivers verifying that you are staying at a participating resort for transportation anytime soon. Easy if this was 1971 and you could show your paper based Transportation Admission Ticket. Not so easy in 2020, when someone is flashing their nondescript MagicBand/Card/Phone. Costly and time consuming.
Number one problem is that they’d need to provide a secure and consistent wireless network connection that they have at the main entrances/resort security booths to check resort credentials.
Then there’s the cost of outfitting the drivers with handheld devices as it would be way too much to outfit the fleet with a touch point. That’s devices plural since you’d need back up devices if one has a low charge or stops working. Likely some sort of charging system would have to be considered since there’s no way they would be able to provide device support if the driver is at a remote resort bus stop versus the major park hubs.
On top of that, you would need to provide training for those Cast Members to operate said devices. Support teams to maintain and repair them.
Lots of money would be lost for the fraction of people who walk over from the Swalphin to use WDW Transportation. Plus it would significantly slow down the loading time for the busses. Disney would be stupid to do this.