Hmmm. Not a solution for me, as I don't use either of those, and no intention of starting, just to get my Gmail notifications.
Will have to look for a freeware replacement. When I Googled, there seemed to be a few candidates. Just curious whether you - or anyone - found one you tried and liked.
Of course, the ones most similar to Notifier may also stop working, because presumably they use whatever functionality Google is about to switch off.