Nah I think they mean that the amount of inventory built up in...

Nah I think they mean that the amount of inventory built up in warehouses would take them 5 years to sell, based on their current dismal rate of sales. From the article:

Bubs said it understood “there is more than five years’ of Bubs Supreme finished goods inventory held in multiple warehouses, based on the current rate of sale”.

Still agree with your basic point though, much of it is nearing or past expiry and is only suitable for stock feed. However, the responsibility for that should fall with AZ Global, not BUB (though this is legally contested between the two).