My understanding, and it's nothing surprising or insightful, is that adherence to basic principles of restauration are being pretty strictly upheld . For example use of side-axes is ruled out and only double bevelds will be employed for hewing the principal elements, realistically, the trusses of the roof. So I can imagine no instance where imported wood would have been a consideration. If you look at the roof's components, even though there is a lot of oak used, (it was referred to as "the forest" up there - either because that was an impression given in that space or because it took a whole forest to provide the wood, who knows, it's ambiguous), the dimensions of these pieces are not all that big, so that should simplify hewing work to a degree.
You know, you could be right in a way to suggest that everyone who's doing work there is not strictly chosen on the basis of the merit of his or her - there were plenty of women involved in our week's work there in Brittany which was a kind of pre-selection exercise among other things - quality of work. That said I'm sure there will be measures to account for quality. And not necessarily by the pros who have little competence, for the most part, in use of hand tools since they rely almost totally on mechanization which of course is precluded at Norte Dame. This is the main role of the group, Charpentiers sans Frontier, to provide some oversight of the huge contracting companies with their strictly commercial competencies.
Whatever, it seems that the carpentry aspect is pretty extensive but the numbers, not so clear to me. I do know that tool manufacturing will involve six or eight tool makers - kind of specialized blacksmiths - who'll be working to make the tools for the carpentry including 100 axes.