Since T8 is the only terminal on the OTHER side of VW exp., walking is not a good idea (especially if you have luggage).
On June 7 at 1:30 pm the inner loop AT was not working; to get to T7 (from T8) one had to take AT to Federal Circle, reverse direction, take AT into JFK, circle loop to get to T7.
Was there EVER a shuttle between T7 and T8?
I don't think there was a shuttle in the past. Like every train network in the NYC area, issues
(inner loop AT 6/7).