Hello Jim
I’m going to make an assumption that by "dropping the datastore", you mean stop the Data Store service (without starting again) or shutdown the virtual machine that hosts it. If this is the case, then any web maps or web apps that rely on hosted services will have errors when trying to load those layers.
However, by restarting the Data Store service or virtual machine, the hosted services should return and continue to function.
If you mean to unregister the data store, then you will lose those hosted services. The way to get around this would be to use the data store command line utilities tools to back up and then restore it.
https://enterprise.arcgis.com/en/portal/latest/administer/windows/data-store-recovery.htm
Another option, which is perhaps easier, is to take a snapshot of the VM before you blow it away and then you can restore it.
Cheers Ed