I asked on a recent visit to the lounge and was told the BA lounge is being taken over by Aspire so unfortunately it is not just a rumour.
I remember the lounge opening a few years after a refurbishment when BA took over BMI. Sadly since then they have axed most of the flights. I recall BA initially had about seven flights a day on some days, whereas now it can be as low as two.
I fear for the remaining few flights a day that are left.