While you're welcome to experiment, I can't guarantee that other moisture-giving ingredients like yogurt, creme fraiche, or milk would work in this recipe as they all have different levels of acidity, fat, and water content. Sour cream works really well in this recipe because it's acidic, which helps to tenderize our muffins. It also adds moisture and creaminess to our batter, while allowing the batter to be thick enough out of the bowl to stand up in our muffin pan. This translates to the perfect combination of a puffy, proud muffin top, while still having a tender and moist crumb. This magical combo is hard to imitate with a 1:1 substitute of a different ingredient, and I think you'll have better results looking for a recipe designed to be made with, for example, yogurt from start. That said if you do decide to experiment, please let me know how it goes in the comments below!