I primarily fly out of JFK on QR and this is news to me. I was on QR704 on Monday and it was operating out of T7 as normal. My advice would be to call QR US customer service a day or two before departure just to confirm if indeed your flight will be out of T8 instead of T7. And worst case, if you get to T8 and see it’s out of T7, it’s only one stop away on the air train. And if this is indeed the case, this is a great move as T7 is an absolute dump.