I, too, wondered what the spices should be and found two potential answers.

This recipe is very like yours but instead of zaatar, the author lists "seven spices" plus extra cumin.

This cook insists Mujadara, should be plain/unspiced, but recognizes variations may use 'seven spices', and has a 7-spices recipe if you don't have a store that sells it pre-made. Note that I have not tried any recipe on this site, but it IS Vegan. I am a bit suspicious because its hummus recipes use CANNED chickpeas. That seems extremely wrong and inauthentic. On one of the the text-walls they do say that boiling dried beans is better, but then don't list that as a recipe version. It makes me wonder what else they are leaving out and not explaining.