Now there are more chances to see him there. And about the following week, as he´s on Aachen Entry List, is it official that he´ll be there or is there any chance of see him in Paris Qualy Entry List?
As far as I am aware, according to the ATP Rules, if a player commits to a Challenger he can't then pull out to appear in another event. It is something to do with contractural obligations and not breaking contact once they have agreed to appear in one place. I don't know all the rules though - but I think that is correct - so - no - he cannot appear in Paris.
Btw - he plans to go to Lyon to qualify but he is very much hoping for a Wild Card either there or in Basel.