That was what they said when they released Crimson ReLive in 2015 and put Terrascale into extended support with promised less frequent but once a year updates.
Terrascale was made legacy in 2015, there was no promised less frequent driver updates.
These products have been moved to a legacy support model and no additional driver releases are planned. This change enables us to dedicate valuable engineering resources to developing new features and enhancements for graphics products based on the GCN Architecture.
Terrascale was made legacy in 2015, there was no promised less frequent driver updates.
https://www.legitreviews.com/amd-ends-driver-support-for-radeon-hd-8000-7000-6000-and-5000-series-cards_175672
https://www.techspot.com/news/62913-amd-ends-driver-support-hd-5000-6000-series.html
https://www.anandtech.com/show/9815/amd-moves-pre-gcn-gpus-to-legacy
in 2015 they have selling 5000 series apu with terascale gpu. Already legacy.