No.
Arnold GPU is based on NVIDIA Optix 6, which is available for Windows and Linux only.
We use Optix 6
Optix 5.0.1 (the last mac version) is from March 2018
Do you know if this will be possible in the future?
If NVidia drivers and NVidia Optix become available on macOS, then Arnold GPU will be available on macOS. That's up to NVidia and Apple.
Could you please answer the question of Loekie Loek.