Isn't there problems with replacing a single cell causing the battery management system to go whacky? I was under the impression that the cells need to be balanced with each other in some fashion.
That said, they don't specifically show/call out replacing an individual cell.
Which don't happen often enough to make Amazon do something about fake packs for drills and Dyson vacuums, but I think the chance increases as cell count increases and idiot-proofness decreases.