I concede that some folks might take offense to the name Gay-Dar, but whether that is positive or negative, tacky or classy, all depends on the angle in which you're looking at this. In his bio, perhaps Gay-Dar takes on this name because he has the power to locate those who are struggling with some issues/facing discrimination and he serves as a mentor. *shrugs*
Being gay shouldn't be a big deal in the negative sense, but no doubt a gay character would be major in the sense that a ton of gay/straight/bi etc. collectors would see it as a progressive step from Mattel.
This may not be true for everyone, but being gay is a huge/important part of who I am. I suspect it is for many of my .org peers as well.