AMD no longer supporting Async Compute on GCN 1.0 GPUs?

Users of older AMD graphics cards discovered support for Async Compute is no longer working on GCN 1.0-based video cards, which includes the Southern Islands family.

A poster at the AMD Reddit group reports the feature is no longer present since the rollout of the Catalyst 16.9.2 drivers about 2.5 months ago. This is hurting performance as Async Compute can give AMD cards a nice performance boost in new games.

AMD Drivers 15.7.1 and inferior to 16.9.2
Compute only: 1. 49.01ms
Graphics only: 47.38ms (35.41G pixels/s)
Graphics + compute: 1. 49.12ms (34.16G pixels/s)
Async Compute works !

AMD Drivers superior to 16.9.2
Compute only: 1. 45.25ms
Graphics only: 47.14ms (35.59G pixels/s)
Graphics + compute: 1. 92.39ms (18.16G pixels/s)
Async Compute broken !

At the moment, it's unclear if this was done on purpose or whether it's a unfortunate bug. Legit Reviews reached out to AMD and heard they're looking into it.