In my example, it's a revenue latitude fair. Although , that should not normally affect the result.
"Cash Latitude" and "award Latitude" are subject to small but critical differences regarding the use of eUpgrades prior to the normal eUp window.
The fact that this thread has discussed virtually nothing else all year, suggest that you're right that AC are doing a poor job of communicating this, but it's still true.
As an end user , if I see "seats available for upgrade " , I base my decision on that, book the flight and want to execute the upgrade immediately.
AC does not honor what the end user sees on the web site in black and white.
You're inferring from incomplete data there. Booking months in advance, the search engine shows "seats available for upgrade" from both Flex and Latitude, and it's true that at the time, it's still possible to use your eUps *subject to the rules of the eUp program*.
You're inferring that AC has broken a promise, when it would be more accurate to say that they're communicating poorly in a way that's very easy to misunderstand.