What usually happens to Marine Aviators after their first tour? Is it true you can no longer fly and have to do ground duties? The only platform I heard that have pilots continue to fly after their tour is the KC-130J..
Not true.
Generally speaking, you do your first tour, go off and attend EWS or be a FAC for about a year, and then go back to the fleet. Other options include the training command, the FRS, MAWTS-1, or some other type gig. Once you make major, you pretty much alternate flying tours (department head, command, group staff, etc) with non-flying tours (MEF staff, HQMC, etc). This is
generally true for all communities.
Either way, even when you are on a flying tour, you'll still be doing "ground duties". Otherwise known as "leading Marines".