Is FreeSync over HDMI not supported in linux even for FreeSync compatible monitors?

I recently made a post about my FreeSync certified monitor not supporting VRR over HDMI. I thought that there was VRR support over HDMI even for versions below 2.1 spec. Am I mistaken in my assumption¿? Has the HDMI forum prevented the implementation of FreeSync in the open source drivers¿?

Obligatory fuck the HDMI forum and the HDMI spec.