Well considering the actual 1989 costume was armor bits on a cloth undersuit, they could replicate it well in this 6 inch format and it might be the "loophole" they need since it's a "doll" and not a figure.
Same loophole that NECA is doing with their purple video game version. Obviously that was allowed since it's not an actual 6 inch figure of the movie version, which for some ungodly reason Mattel doesn't want us to have. I can't paint, so I won't be buying the purple Keaton.....but if Mezco makes one as awesome looking as these DKR figures??? I'll buy the living **** outta that!!!