In my opinion, BA have done nothing wrong. They have used ‘old’ frames on many routes over the years, it’s just what the market dictates and what aircraft is necessary. BA are a business and unless Ghana is giving a subsidy/PSO, I don’t see why they should tell BA what planes/terminal/airport to operate from.
The decision to switch the route to LGW may be unfortunate but that’s BA’s decision. ISB and DOH are also moving to LGW and they aren’t kicking up a fuss. There are so many routes which only have a LGW connection (KIN, ANU etc) - that is just the way it is. It’s not racism or discrimination just business.
Also, by switching to LGW the route will benefit from BA’s new refurbished 777s. They’re much better than the 747s which used to run the route.
The thing is, if BA pull the route I’m sure Virgin will take it up or the government will subsidise them to operate it. So BA doesn’t have all the power.