I think Disney will do anything it can to keep people going DHS-->Epcot and Epcot-->DHS from neeeing to make a cab change. Changing cabs is a headache and a completely unneccessary step where any number of things can go wrong (person is slow or slips, struggles with an
ECV or stroller, etc).
My thought is that Disney will make multiple queues depending on your "final destination." Think of it like leaving MK and choosing your line. One line to resort monorails, one line to TTC monorail, one line for each boat line etc.
Hypothetically, let's start at Epcot. Load cabs to Riviera, CBR/Pop/AoA, and DHS. Rivera gets its own queue for being a "deluxe" differentiator. CBR/Pop/AoA ends at CBR, and you transfer to Pop/AoA. More headache, but "value." You'd also be able to ride through to DHS without your cab unloading even once.
Lets say you're going to DHS. The system knows your cab is going to DHS so that it passes through Riviera and CBR without opening the door to load/unload. This allows cast members to focus only on loading/unloading cars "ending" at that destination. This eliminates the headache of tending to *every* cab and having people getting on/off all cars at every station. Further, cast members can direct the appropriate number of people to a preload spot knowing they are loading an empty cab. The alternative is every cab has people getting on/off and cast members not knowing how many spots are open until people exit, and that just sounds like chaos (two people here, four there, etc).
Within a station they could probably design it to have the unloading car at its final destination go one way and the continuing cars go another. (Supporting the idea that cars exit the cable in station and travel by rail in station).
Its 2018. Im not expecting a guy in a room pushing buttons but a computer that is well programmed to not only recognize line capacity issues in real time but have the ability to predict problems (e.g. "OMG we just loaded a cab full of
ECVs, thatll need more time to unload"). The system knows queue length and how many cars for each it needs, and adjusts itself. It can adjust for bottlenecks and send load fewer cars to a final destination if that station begins backing up, then resume regular service when cast clears the kink. This might mean occassionally passing an empty cab through but the potential efficiency gains in other parts of the system can justify this.
So what are the hypothetical queue choices based on where you hypothetically start?
Start: Epcot
Choose one of three queues: Riviera, CBR/Pop/AoA, or DHS.
Start: Riviera
Choose one of two queues: DHS or Epcot.
No choice to CBR. You can walk to CBR and then choose to take Pop/AoA line if thats final destination. Why? Riviera and CBR are too close to warrant a dedicated destination que.
Start: CBR
Choose one of three queues: Epcot, DHS, or Pop/AoA.
This is most widely accepted from the plans amd our theories, minus my thought that there will not be a choice to take a gondola to Riviera as final destination (walk it).
Start: Pop/AoA
Choose: CBR is only choice before needing to transfer.
Start: DHS
Choose one of 3 queues: CBR/Pop/AoA, Epcot, or DHS.
Same idea as Epcot, but reversed.
Again, that's just a theory.