Thanks for all of your responses. Although I haven't made the change yet (I've been directing my irritation with corporations at EDF more recently), everyone I've spoken to seems to have been able to switch and not lose - or pay for - their btinternet email. From what I gather, at some point BT Group made the decision to use BT as a business-only brand and have home consumers served by EE. I think that's the change that probably removed the barrier to keeping a free btinternet email address, as it would assist BT Group in refining their BT and EE customer bases.
@19tonyd, it sounds like you've got a strong case for a refund!
When/if EDF stop annoying me I'll sort out my broadband and will post a further update here on how it all goes.
