Funcom is a business. They are here to make money. They have other interests outside AoC. I never liked how AoC partially funded these other interests while very little was returned for subbed players, but I get that there is a bottom line to achieve. The only thing they should have done was let players know beforehand that the actual anniversary content was only limited to double AA points, and that they were releasing a small adventure pack that was optional PREMIUM content that could be bought.
Instead, they offered up some update letter without ever mentioning the word "premium", which would denote that it costs money. I am guessing they knew how it would be received with how they did this, but disappointing the AoC community is one of the things Funcom does best.
Someone could have at least apologized for leaving out the fact that the content would cost additional money, which clearly the community managers could have done, if even on the forums.