I think it is a fair generalization at this point. Mbuti also have a ~6% West Eurasian admixture signal using an ancient (4.5kya) Ethiopian individual as reference, though Pickrell 2014 did not see it. Decimal dust, perhaps? https://www.science.org/doi/10.1126/science.aad2879

The ghost admixture story(s) will turn out to be much more localized, I imagine.