Yes it is correct. Did you not read the part in brackets of what you quoted?
Free exit row seating longhaul is a Gold benefit and can be selected from booking. Exit row seats will show as blocked to all others until 14 days prior to the flight when they become available for payment.
Silver Members (oneworld Sapphire) – free seat selection from the time of booking for everyone on your booking (except on hand baggage only fares and not including exit row or bulkhead seats on longhaul flights).
http://www.britishairways.com/en-gb/...sing-your-seat