No, it is part of the update. Look at the Compiled Errata pdf from October.The Essentials changes that were a separate document and not part of the normal errata are not included. So, those changes come into effect October 25th. I don't think there were any Essentials changes in the normal October update.
If it is now in the official update/errata pdf, it should be available now.
I almost never look at the monthly pdf. It is easier to check with the compiled to see any changes at once.