A few more datapoints before my flight this evening:

1. When I tried to book my original flight, I needed to use Reservation Assurance to get a seat as the flight was oversold. However, when I tried to do this, I was told I couldn't use RA as the flight wasn't operated by BA. Luckily the meeting moved as I would have been really unimpressed if this were the case.

2. The seatmap changed on ba.com at time of checkin from a seatmap with 3 exit rows (10, 11, 12) to a seatmap with 2 exit rows (11, 12). Luckily as I am in row 12, this should be OK.

3. My BP on my iOS app has come out as completely white - with no tier info and no fast track.

Will report back if any other "oddities"