I don't have much information but I know for sure that training has started in GCLA (SAERCO), LELL (Ferronats) and will start in october in LEVC (Ferronats). I don't know how it's going in the rest of the privatized twrs.
From what I've heard, there are ATCOs from several nationalities (I've heard some british and polish, but not too sure about this), former spanish military controllers and spanish controllers recently qualified under the new (shorter) system.