I'm trying to figure out how things like steam early access and betas you can give money to (i.e. most free to play games) effect the release date of a product. Is the release date when they say it is out of beta or is it when you can give them money and they give you a game? I've always tended toward the latter definition and I was wondering what everyone else thought.
Since Early Access games are in their own category on Steam and clearly marked as being in development or in beta, I don't think it would be appropriate to use the Early Access start date as their release dates. It seems to me the best way to handle this would be a short statement in the body of the wiki article about the game's Early Access availability and related dates.
That's just my opinion though and shouldn't be looked at as the site's stance on how these games should be handled. That will be @jeff's call.
Keep in mind that not all "Early Access" games are created equal. There are games out there being released in all varieties of alpha/beta release, many of which are barely games.
I personally wouldn't use the public release of an alpha/beta as an official release date, but it probably does warrant a mention somewhere in the body of the wiki.