My first kilt was made up in the Fraser Green Gathering Tartan, which is similar to a theoretical Coronation tartan in that it was created to celebrate a special event. I chose it because a) it had the name Fraser associated with it, and b) it was green.

I am certainly a small sample size, but I suspect that the name of the tartan itself won't have much to do with the sales - rather, the aesthetic appeal of the tartan will make the biggest difference. I would bet the fact that it celebrates King Charles' coronation will be of secondary concern.