I imagine rebranding from such a mouthful, which sounds like it would cater only for a bunch of old WASPs to Folk England, makes them seem a bit less formal which makes it more inclusive for younger people (who without which the society would eventually die)

The former name sounds like a village fate committee (which immediately makes young people balk), the latter sounds like a bunch of other our national cultural institutions with two word titles;

English Heritage, National Trust, etc