It does seem surprising to me that an airframe with known pressurisation issues wasn't taken out of service right away. It also seems odd to me that two seats next to the relevant window were apparently empty, two of only seven unoccupied seats in a full flight - including a window seat at that. That suggests that these seats were not bookable, which further suggests that something was known about that area of seating. Whistling noises? Rattling? Cold breeze?