I have a theory. I am just guessing, but having watched their robot in action, I can say it is a slow, clunky bot that can't likely be used when restocking shelves, as people get in the way. If you block its path, it stops and sounds an alarm. They were using it when customers were in the store and it had the same problem. Customers get in the way and it sounds an alarm, the recalibrates it's path. If I had to guess, they are probably holding out for something smaller, faster, more agile. There could be other factors. No idea how much that thing costs.

Yea I think that's correct because pandemic shifted priorities for Walmart, autonomous solutions aren't yet good enough to completely replace human workers. Online orders spiked which left human employees with more free time so they were moved to storage and inventories to fulfill online orders and pickup orders.

WSJ reported it good: "As more shoppers flock to online delivery and pickup because of Covid-19 concerns, Walmart has more workers walking the aisles frequently to collect online orders, gleaning new data on inventory problems." [1]

[1] https://www.wsj.com/articles/walmart-shelves-plan-to-have-ro...

Very reasonable guess, at the end of the day, these jobs will finally replaced by robot, like it or not.