Some people (including BA advocates on the forum from 2 years ago) are missing the point, the issue is not so much about whether there is enough space or not to store food for two meals...the galleys are simply too cramped for the crew to be able to execute service well especially in WT and WTP. As others have posted above, BA is the only airline out there without a galley at door 2 (Even VS has a galley behind the Loft area - check some cabin tour videos for evidence). Combine that with a small back galley and you have a recipe for disaster service wise.
Also interesting quote from the TPG UK review of WTP on A350 below which gives you a flavour of service on board:
The meal service should be tightened up. It was ridiculous that the lunch took more than half the flight, especially when the trolleys were constantly being wheeled back and forth.