There is no master list of the European schedule with start dates, etc., at least not on FT or at aa.com.

The easiest thing is to just use Google Flights to search the routes you're interested in. For example search PHL-ATH, then set the filters to one-way, nonstop only, AA, then click the calendar, the dates with prices are the dates the flight is starting and/or operating on. Looks like PHL-ATH is scheduled to start on Aug. 17 as well.

AA is already flying to CDG from JFK and DFW a few times a week.

It's of course possible that European flights in general could start back up sooner (or later) depending on how things go with regards to countries opening back up, vaccinations, etc. The schedule to Europe has been in a constant state of change for the past year.