Grand Rapids has a new dean that is trying to get a broader applicant base. All of their residencies other than ortho and plastics tends to be very inbred with MSU people and Michigan residents. He has started sending out these fliers, as well as arranging free housing for visiting students with local attendings to get more people from outside Michigan to look into the many residencies offered. Now to answer your questions specifically.
1. I am not sure if he sends them to every student in the country or not, but I know that he sent out several thousand last year.
2. Grand Rapids is not hurting for applicants, other than their internal medicine program, they tend to fill all their residency programs with well qualified US grads.
3. It may be a tad early for you to apply for aways, but it is never too early to start thinking about it. It is also really nice to have a place that will let you apply as early as you like. Many places make you wait until March or April after they have let their own get their spots.
If you have any questions about GR ortho specifically, feel free to ask, I will answer your questions to the best of my ability.