From WSJ: Amazon Says Email Ordering Employees to Delete TikTok Was Sent in Error.

I suspect Amazon realized late what a legal mess it is to ban an app on their employee's cell phone when they have no clear legal basis or governmental guidance. They banned employee using Huawei phones when I was working there, for some things -- don't remember exactly. But in that case, US government already banned it for its employees, so there is precedence Amazon can claim as legal basis.