They seem to indicate that there is something definitely "African" about this collection of mummies. I have previously used PopAffiliator and STRUCTURE with CODIS markers. The results of that analysis suggest that even this small number of markers is sufficient to place a sample in a continental group with high accuracy, but insufficient to estimate levels of admixture. There is a new version of PopAffiliator, which, unfortunately, does not allow for incomplete data entry, and hence cannot be used to verify the results of the DNA Tribes analysis.
The DNA Tribes results are interesting, but may hinge upon a few marker values that are more prevalent in Africa than in Eurasia. Also, it is not clear which population(s) make up the "North African" group. It would be interesting to extract full genome sequences from Egyptian mummies in order to properly place them in the global genetic landscape.
Pictorial evidence in Egyptian art, as well as the statements of classical Greco-Roman authors strongly suggest that the ancient Egyptians occupied an intermediate position in the phenotypic continuum between Near Eastern and "Ethiopian" people. It is also clear that there was variation within ancient Egypt itself: geographic, temporal, and even perhaps social aspects of this variation may have existed. But these qualitative observations are no substitute for the harder type of evidence that can be provided by authentic ancient DNA.
Hopefully, the debate on the genetic identity of the ancient Egyptians can proceed on the basis of new data, although I am not holding my breath that this will happen anytime soon, both because of the fluid state of politics in Egypt itself, the existence of various fringe theories outside of Egypt, and, the rather controversial state of mummy DNA analysis itself.