British Airways Silver & Gold members + Oneworld Emeralds have been able to select seats in advance without having to pay seat selection fee. This has applied to non-Hand Baggage Only fares.
It was noted on Flyertalk (access here) over the weekend that British Airways no longer allows this, but has blocked all the exit row seats up to 72 hours before departure. This applies to all short-haul flights.
Here’s example of London Heathrow to Istanbul flight in March:
I am British Airways Executive Club Gold member (soon Gold Guest List whatever that is worth) and all the seats up to the exit rows are blocked, although there are no seats reserved.
Conclusion
This is very unfortunate development. The second row of exit row has more leg room than the Club Europe seat in business class plus they recline too.
These blocked seats should become available for selection 72 hours before of the flight, but many (myself included) have better things to do in their lives than babysit airline reservations for seat selections.
This could be reason for some to fly less on British Airways and choose other airlines instead.