To put that into perspective: I have got 32 warnings over the last 3 days, each of which is of course an expected notification, since they all are related to the snapshot tasks, that are assigned on the slave volume.
The problem is, and I bet that you'll be with me on that: if one gets repeated warnings or errors that aren't really errors, people tend to just skim over them and are risking to miss the one important error, that they really should have paid attention to.
If I am getting 8 e-mails a day from my DSS hosts, I will start to think that everything is okay, solely based on the number of messages I get. We all know that this shouldn't happen, but if a system runs reliable for a period of time, I guess nobody can help him (or her) making that shortcut - especially if you have to take care of dozens of such systems, which all fire messages at your inbox.