Unless something has changed, Walmart does not want its suppliers to use AWS to mitigate that very risk.
https://www.cnbc.com/2017/06/21/wal-mart-is-reportedly-telli...
https://www.cnbc.com/2017/06/21/wal-mart-is-reportedly-telli...
So you can both do this (silently) and "not" do it (because it's impossible to detect), and it would thus be stupid to not actually do it because it's free data.
Zooming out I think this and the opposite view are equally possible. Just articulating what this perspective looks like.