That "theory" was proposed by Adams et al. to try to justify some of their fishy claims, but it doesn't wash. First of all, the majority of "Moriscos" were just former Iberian Muslims, not people of foreign descent (in other words, most of them weren't really "Moors" to begin with), and second, I don't know about you but I have never heard of any such large-scale movement of them to the North West of Spain. Most people have heard of the large-scale expulsion of them from Spanish soil in 1609 and 1611, though.
The repopulation (new people of diferents places from Spain) of Granada is historically registered, the fear of the spaniard because these muslims could ask for help in North Africa and the Turks empire and starting a new conquest.
I know what only 6-7 % of population of the Iberian population was african and the rest were just religious converts but think what Granada is the last muslims reducts (city,land) in iberian and for 2 centuries, all a lot of muslim or african people, everyone fled (moved) to Granada.
These muslims where separated in relatively small groups throughout the country northwesternt, Galicia and Castilla and intragrated well abandoning their religion and escaped the expulsion od 1609 ect...
Im sorry, I can not explain me better in english
I will try in Spanish the same text.
Entiendo que la gran mayoría de granadinos anteriores a 1492 no eran africanos pero no me cabe duda de que el porcentaje era superior al resto de provincias españolas pues los musulmanes fueron escapando poco a poco a esta ciudad confirme iban perdiendo terreno en España, recordemos que Granada además era más grande que en la actualidad.
Tras la conquista y las revueltas de las Alpujarras, las prosas y escritos secretos sobre el guerrero verde de islam que circulaban narrando que vendría a recuperar la península para esta religión y el poder turco en auge el miedo hizo que se movieran a todos los musulmanes de Granada al noroeste, alejados del levante español y del mediterraneo, fueron separados cada cierta distancia en poblaciones de Calicia y Castilla, y bueno no todo pero si una buena parte de esos genes debería encontrarse hoy en día fuera de Granada, en esas zonas.
Recordemos también que los musulmanes hicieron una criba de cristianos en el años 1125 expulsandolos al norte de Africa o exterminandolos debido a que se rebelaron en Granada, o sea menos cristianos viejos y más musulmanes en esa zona.
Im sorry for using my languaje, I say the same as above in english but without mistakes/errors.
Greetings.