Update: Just received an email from AMEX asking that I disregard their prior email about the bluebird card that, they say, was sent in error.
Dear Bandana1948,
The account closure notification e-mail you received today was intended only for bluebird Cardholders. Please disregard the email and the information contained in it. We apologize for any concern it may have caused. Your American Express Prepaid Card is not impacted in any way, and has nothing to do with the account closure notification email you received in error.
Sincerely,
American Express Customer Care