You should try owning a Motorola for a bit, you would think HMD are magical wizards blessed with unearthly powers then.
So long? to date, we have all received monthly security patches... on the respective month. It is at beginning of the month, in the middle, at the end, who cares?
update is now available;)
See? Just a bit of patience!
For a perspective: My wife's Nexus 5x received the September security patch on Friday 14th of September. Usually she receives those updates on the 4th to 7th each month. So I guess, Google was late to release this month.