This sounds interesting: the sweetness of the dates would change the different flavor, but I think it would be in a good way.
I've made tabbouleh many times (and, in fact, just writing about it is making me want to pick up what I need on the way home today so I can make more). One day, I made some for my gluten-intolerant brother, so I removed the bulgar wheat. It tasted just as good to me, so now this is now how I make it. Typically, I use these proportions:
2 bunches parsley
1 bunch mint
1 tomato
1/2 small onion
3 tablespoons lemon juice
salt to taste
Many people will add olive oil (I would have used the same proportion of lemon juice), but I've excluded that to keep the calories down. Again, I don't miss it. You'll note that there's a massive amount of mint compared to most tabbouleh recipes. That's entirely intentional.