I'm on the same flight, stuck in the lounge. I'm sitting in the corner, against the far wall, near the buffet counter.
I first noticed the delay at 2PM CET and called BA to try and get them to move me to the BA941 since I'm connecting to the BA199 to BOM this evening.
I checked in at the airport at 3PM and tried once again but the answer was no. (I'm on a full fare Y class ticket)
I missed a similar connection from FRA a couple of weeks ago, there too I noticed the delay well in advance and tried to get them to move me, but to no avail.
I'm currently a Gold with a very low CIV (95% of my flying is Y or Y+), I'll cross the 'magic' 5000 Tier points barrier next week, I wonder if that will make a difference in how BA treats these sorts of issues.
To add insult to injury, I was moved from 6C to 22C since the curtain was moved at the last minute.