Isn't it at best extremely misleading and at worst a complete scam for BA to say that for economy passengers there is free seat selection at T-24 when in fact their system automatically allocates all seats before reaching T-24? On a mostly full or completely full flight there ends up being no free seats available at T-24. Just had that experience on two long haul flights.
In effect there is no real free seat selection except for less than full flights where a few odd seats will be available to choose from. They certainly dont disclose that they will be pre-allocating all the seats at T-72 or whenever.