Hi HunkyBill,
The billing I am referring to is for our app not Shopify, our app is not free. This means that we need to know when to appropriately charge our customers.
We are already successfully using the app/uninstalled webhook, however this webhook is not sent if a store is closed (I guess technically the app has not been uninstalled). In this case, we don't know if the shop is temporarily closed or permanently closed.
It looks like what we'll have to do is assume that shops are temporarily closed and then suspend their account and stop charging them in our app. I'll have to do more testing to figure out exactly how this will work if it's possible.
Thanks again!