I am going to clarify a few things, and MisterLucie I am just quoting you to provide context to my response.
FFXIV has live letters, with Yoshi-P and that is something far more relevant than a single developer, and he does it way more often. SE has both written and live responses to the community all the time, I honestly don't think you can compare Blizzard to SE because they are not nearly as interactive. SE also goes all over the place for the fan festival, listening and communicating with the playerbase.
For those that don't know, when you create a PV or in this case a Preview of the game to be presented you have a team that puts it together in conjunction with development. They were never going to have the latest version, and the warning that things are subject to change is simply because when they bundled it up back in April they had no way of knowing how much would change. The game was essentially a closed beta at that point, no one should expect every aspect to be done.
It is understandable to be emotional, but before you go on a mission to burn the world to ash, it would be helpful to analyze what you are truly mad about. I saw youtube videos on every class, minus black mage and there was plenty of complaints about white mage, but they also mentioned... well everything is subject to change and no values are permanent. It is also hard to say at what stage when they bundled up the game for the preview that the white mage even was in completion. They had more then a month to finish up classes and their are a lot, some were going to be further along then others.
Lastly unlike Blizard the dev's have a language barrier, They can't just read what you say, or even respond to you efficiently. How many people can scroll over to the Japanese forums, read their posts, and then respond to them? Let alone be a developer for the game in question where mistranslated become Lies. Watch, Listen, Think, Feel
This is of course... just my opinion so feel free to scroll to the next post ^_^