Generally speaking, the suggestion not to store fixed blade knives in their leather sheaths comes from experience with carbon steels. Stainless steels generally have no similar problems. While high carbon stainless steels, including CPM S35VN, are not quite as corrosion-resistant as lower carbon stainless steels, I still wouldn't expect any problems with your White River. More so with you having coated it with Tuf-Glide.