One common answer is that they still have work to do, but Walmart will put that work on remaining employees to save a dime. If this is true, why wasn't it being done before? Why is there that much wasted slack in employee productivity potential?
Another common answer is that they hired too fast and now need to readjust for future expectations. This makes sense in terms of smaller startups who may have miscalculated market trends and have limited financial runways, but for the largest private employer on the planet? Who is financially profitable and self-sufficient? Really?
Does management simply pay zero attention to headcount and payroll until a bad quarter happens and then they start cleaning house?