Best Buy's network of stores and website are the largest single channel Navarre has to get its customers' goods to the consumer, yes. Both corporations are headquartered in the Twin Cities area, so that makes sense.
But it's not the only channel, and Navarre's customers already rely on them to open other channels. Since that's what they do, anyway, if Best Buy were to go away completely, I'd expect to see other vendors that currently sell predominantly through Best Buy coming to Navarre for product placement services elsewhere in their network of contacts.
What would be the basis for fearing that if that were to happen, consumers would just stop buying the stuff that Navarre distributes? Why would they not go to other sources, like Target, Walmart, Shopco, Costco, Amazon, Staples, etc. Personally, that's what I'd do. Navarre distributes to all those, too.