Your assumption that they would not have attempted to make further contact with you once they had failed to reimburse you via the normal method seems to be a result of annoyance at having the account closed rather than having any basis in fact.
I don’t "assume" anything EF, just asking the question what would’ve happened. It may be they would’ve got back in touch when they had tried, but the e-mail is still wrong. If they weren’t aware my details were not up to date then they should’ve been. They’ve obviously had people using winnings as their betting money before (identical situation to mine). If they can look at the account closely enough to close it, surely they can look at the other details. If it was the "generic" standard message, then they should make sure the "generic" standard message is applicable.
Look, it’s no big thing, just warning other people what might happen if their account is closed.