Apart from Alves, most players won't be available right now anyway.
The deals shouldn't be finalized before the assessment you write about, but of course Xavi should have a sense for the market, and that he seems to consider Alves, Pedro, Thiago is natural and good!
I think with Alves he is going for the Davids effect, and I obviously can't doubt Xavi footballing brain. I will add only that this is where a top Sporting Director comes in that understands Xavi to find the profiles he wants and needs.
I do wonder though that this Alves move (and who knows whats coming next) is part of the reasons why Planes stepped down.