I know for Wisdom Panel, they told me that the unknown portion was basically indicating that certain breeds came up but with very low confidence so they indicate if there are common “types” among the results. I specifically asked about German Shepherds as we figured he had GSD ancestry given how common they are and his appearance. Customer service was able to let me know that one of his main “low confidence” breeds was a Berger Suisse Blanc.
With DA, I think the unknown portion is simply an issue of certain breeds not being mapped yet. I imagine it will be a “bully type” breed but maybe it will be some of those “low confidence” breeds that WP referenced.