https://wccftech.com/amd-graphics-cards-and-consoles-will-work-with-future-g-sync-displays-nvidia-confirms/

In a rather significant change for AMD graphics card owners, NVIDIA has confirmed to TFTCentral that future G-SYNC displays will be able to run on the competitor's GPUs as well.

Over the course of 2019, NVIDIA has considerably changed its approach to G-SYNC. Firstly, they announced the G-SYNC Compatible program at CES 2019, opening up the VESA DisplayPort Variable Refresh Rate (VRR) standard Adaptive-Sync to be used with NVIDIA graphics cards. While the number of compatible displays ramped up over the course of the year, users were already free to try and enable the feature manually on their Adaptive-Sync displays, even if they hadn't been yet certified by NVIDIA.