July 4th is an American holiday, not a Mexican one. I don't recall much going on in Playa that day but maybe someone local will know more.
Because AI resorts are frequented by so many Americans, some do have some kind of celebration - I know the Now, Dreams and Secrets resorts do, mainly because these are American owned hotels. I can't say if the Catalonia will, not being owned by an American hotel. It may be business as usual or there may be some kind of event. You can try sending them an e mail to ask if they will be doing anything special that day, or ask on their Facebook page.