It's maybe also worth downloading the Expert Flyer Seat Alerts app. You can use it for free to see what seats are taken on your flight in each cabin - whilst it's not definitive, as not everyone will have pre-booked seats, it can help to show how busy the flight is looking. There's also a thread on here somewhere where you can ask people with the paid for Expert Flyer to check the flight load - they will be able to tell you how many seats BA are still willing to sell on that flight. If there are only 2 or 3 business class seats on sale then there's likely zero chance of them releasing Avios seats, if there are 9+ then there's much more of a chance. As another poster mentioned, it's definitely worth setting up an alert on SeatSpy so that you're notified if any seats are released, although that doesn't cover the additional availability for companion vouchers, which are more likely to become available.