The had some K/Mai promo art right after the arcade release (or around that time) which made people think they would be the console exclusive characters. I'll try to find the pic but not exactly sure where it is.
I'm happy Liz got in because I've liked her since she showed up in XI (used her as leader) even though she sucked. She was in promo art even before the location tests so I kinda thought she would show up.
OK I managed to track it down and now it all makes sense. http://kofaniv.snkplaymore.co.jp/top_j.html
notice the original source for the art is not a KOF12 site specifically, even if it is the same artist who does the KOF12 artwork. I see maxima and blue mary there too. they must have done the art ahead of time but the actual characters for the game aren't ready. people saw the art (myself included) and made too big of an assumption