In answer to your query regarding those who have taken upgrades. The AOA has never had an upgrade ban, nor will it. Here's why:
Recruitment bans - will never stop new recruits from coming - but they're not meant to. They are enacted to make it difficult for the company to attract quality recruits. It also creates a friction that, despite what you may think, the company does not want on its property. It is, in fact, a burr beneath their saddle.
Upgrade bans - will never stop some crew from accepting upgrades. They would create divisiveness within our own ranks, and print a license for the company to ignore agreements, direct-hire captains and promote out of seniority. It is, in fact, a burr beneath OUR saddle.
Though once considered and debated (as the GC will do with most industrial suggestions), representatives from IFALPA, APA and ALPA all strongly recommend against upgrade bans. Their recommendation is the result of 80 years of airline labour history and the evidence is clear.
And the best reason yet not to impose an upgrade ban comes from the DFO. While bemoaning the effects of the recruitment ban, he taunted the AOA to avoid hypocrisy and invoke an internal ban - and remember that Uncle Ken is not competent to write his own missives, so where do you think that little suggestion came from?...