Received a response from the
D23 team. The cancellation email was a mistake. However, upon checking DH's D23 account, it still hasn't updated like it was supposed to today. So, technically, his membership expired yesterday and...? All the information looks current, so we'll see what happens. D23 said to wait for several days to see if the renewal goes through.
ETA: Just received an email from D23 saying that DH's membership renewed without any problems. I went to D23.com to double check that everything was in order, e.g. right membership level, and it was. Sigh of relief...