I would have thought that it would be easy enough with a computer-controlled auto box to sense "overrun" when the wheels are trying to drive the engine and to change down a couple of gears to achieve some engine braking.
Failing that, you could always use the "L" setting (equivalent to changing down in a manual) which since the early days of auto boxes has forced the gearbox to change down - probably so it uses one or two of the lower gears according to engine and road speed.
The difficulty with older autos was moving the selector from D to L without the car lurching as it changes down and incurs extra engine braking rather suddenly; in a manual you'd be able to increase the throttle to match the lower gear and you'd be able to let the clutch in gradually to "smooth over" any remaining mismatch. I imagine that is less of a problem with a modern auto.