I still think pullet on that GLW. From my experience, wyandotte roos don't have that even lacing. They have blotchier patches on the wings and back that gradually turn into those pretty saddle and hackle feathers.
I have a EE rooster that we did not know until two weeks ago that he was a he never crowed at all and still looked like a hen until he molted then poof crowing and a rooster tail happened and he is almost twenty weeks old.