Sharp Brothers Seed Company of Missouri has used this method on one occasion, and though I was not involved in the establishment, I am very familiar with the results.
Blackwell switchgrass was broadcast seeded on the snow into two fields which had been earlier sown into wheat. The wheat was allowed to mature and a crop harvested. The straw was then baled and removed. The following spring the fields were burned in mid-April. Soon after the burn, the fields began to green up and resulted in an excellent stand of blackwell switchgrass. The fields have had a productive history since then.

Results from this instance have been excellent. One can surmise the reasons for such good success. The cold moist stratification of overwintering helped to break dormancy in the seed. (Switchgrass is particularly known for high dormancy rates, although Blackwell is typically not as subject to this as Cave-in-Rock.) Freezing and thawing worked the seed into the soil to the ideal depth for good germination. The only drawback is that is just one example. I feel that this technique needs to be repeated several times with similar results before I would feel 100% comfortable with it. However, the results have been encouraging enough. Frost seeding switchgrass does merit consideration.