Before you get excited about 500-600 guys over 60, how many of them are actually senior to you? In my newhire class, 3 of 8 are over 60 and all 3 of us are in the bottom 100 on the seniority list. Other classes will vary but the old guys are not all at the top of the list. As someone mentioned above, the average age at NJ is probably mid 40s and it may be less.

Assuming no reduction (ie furloughs), you can expect to stay wherever you are now until the economy picks up significantly. That is the way business cycles and a seniority system have always worked. Over a career, there will always be periods of stagnation along with, hopefully, growth. Many pilots forget how much luck and timing affect their careers no matter how good they think they are.