Here's a quote taken from a USA Today article on the uniform unveiling:

The Wolverines uniforms merge elements of jerseys from throughout the school's history. Player numbers also appear on Michigan's famous winged helmet for the first time since the late 1960s.

"The compilation of elements from different eras of Michigan football makes this a unique and special uniform," Michigan athletic director Dave Brandon said. "Our players have seen other schools and professional teams wear throwback uniforms and will now have an opportunity to showcase our tradition in a melding of styles. This will be a special event for our football program, the University of Michigan, Ann Arbor and all of our fans."