It seems to me like WF is trying to avoid a bud light situation. Employees wearing BLM stuff will certainly put off a lot of people in many areas. So it’s about not alienating a big portion of their customers, which would be a significant hit to sales.
Anyway, I find it odd to some extent that a business was not allowed, possibly, to limit what employees wear, especially if they interact with customers. A key tenant of sales and customer service is to make the person feel respected and to take an interest (fake if nothing else) in the customer.