YouTube disables comments on all auto-generated Art Tracks, including those distributed through eMastered to YouTube Music.
This restriction is enforced by YouTube and is beyond the control of eMastered or any other distributor.
That said, you can enable comments on these Art Tracks by setting up an Official Artist Channel (OAC).
You can also learn more about YouTube Art Tracks from Google’s support page: https://support.google.com/youtube/answer/6007071.