I did post a detailed complaint to BA, in which I asked a number of specific questions about their decision to offer this as a meal, and to use the A321 on this route, and just received the following very underwhelming response:
Thank you for your email dated 22 April 2014. I apologise for the delay
in our response. We are sorry we were unable to provide you with the meal
service you would expect on your flight to London Heathrow due to
operational reasons. I can understand how disappointing this must have
been for you. Please accept our apologies.
This was followed by a couple of standard paragraphs about how seriously they take customer feedback.
Looks like I'll need to think twice before flying an A321 anywhere on BA again.