So I asked Barclays whether I could upgrade the legacy Aviator Red World Mastercard to a WEMC (like the new Aviator Red they just started offering again). Mind you everything is the same except the product grade and the AF. Here is their (headscratching) response.
Thank you for contacting us here at AAdvantage Aviator Red World MasterCard in regards to your request for upgrade for annual fee card.
We appreciate your interest with upgrading your account to the AAdvantage Aviator Red World Elite MasterCard product. We have reviewed your account, and we see that you currently have the best available product for you at this time. Please keep in mind, we may offer upgrade from time to time. If any offer becomes available, we will notify you directly. We apologize for any inconvenience this may cause.