Why not leave him on as an honorary member? Just like universities give honorary degrees to people who never attended but who's work in real life the university wants to acknowledge?
Let's not have the Bitcoin Foundation be as self-aggrandizing as most modern universities. They're not "acknowledging work", they're cleverly associating themselves with famous smart people for marketing purposes.
Which is exactly what the Foundation did by pretending it was in any way associated with Satoshi Nakamoto. Bruce is correcting that mistake, he is also the only reason I now wear the foundation badge as my avatar.