You know, i have to ask....are the people playing the demo PURPOSELY choosing the old costumes? In all the streamed videos i've seen, all i seen was new hairstyles and Marie Rose's contest winner outfit. It's getting fustrating not seeing all the new costumes..
There are probably several reasons, why so few people show off new stuff, I could imagine:
1) Many, even though they are DOA players/DOA fans, don't follow every bit of news and information, like we do. They might not even know, there are new hairstyles or new costumes.
2) Even in these small tournaments for fun people are under stress. They go directly for their character, choose a costume they usually use/like and the match begins. They wouldn't dare to play around for too long in the character select screen.
3) As there is a slightly new interface ported from the arcade, when selecting a character, people might simply not get, how it exactly works at first. So they press the buttons they usually do and get the same old stuff.
4) Much of the content, that was shown in the trailer, hasn't made it into the demo yet. For example Crimson stage or apparently several of the new hairstyles. I was told before, that there were no new costumes either in the demo. But eventually there were...
5) Some people generally don't care for all that extra stuff. They just want to fight and maybe take a look if their character was buffed or nerfed.
6) Most people don't record their play on the demo stations. (It's actually a little impractical to record with your cam or phone while playing at the same time. XD.)
7) People are a**holes!!! >__< They just don't care, if some of us nearly die at home, not seeing their costume in action, even though looking through video and video and video! ;__;