If they are Win2k Pro SP4, then they have the registry key indicating AD is present, and they have the vulnerable file this patch is relevant for. We tested applying the patch on Windows 2000 Pro SP4, and the patch applied successfully.
Supported Operating Systems: Windows 2000 Service Pack 4
So we will leave the fixlet as is for now. If you need to exclude the Windows 2000 Pro computers, we can provide a relevance to detect Windows 2000 Server only. You can create a custom fixlet with that in place.