Since Igor is one of the senior avast developers, if he doesn’t know or have access to someone that know the avast update cycle then I don’t know who does. So I think his conclusion is likely to be pretty accurate.

Whilst not wishing to put words into his mouth. He is saying that because this update cycle is variable to spread server load there really is no way to tell if someone has missed the update notification or they simply haven’t received it yet; not that they won’t get it at some point in the extended update cycle.