We experienced a problem with firmware updates last fall. Without any notification, Tesla moved our car to the "do not update" list because several attempts to download the firmware to our car failed.
After not receiving updates for an extended period, I called Tesla's phone support, they looked at the logs, and told us we would need to take the car in so the service center could manually install the update. And since then (we think) the car is updating normally.
Since it's possible for a car to be blocked from receiving updates, without any notification, then owners should contact Tesla if they are concerned they haven't seen an update for an extended period.
And, if enough customers do this, it may encourage Tesla to provide a better way to get the status of software updates - or even better still would be the ability for customers to request the update be sent to their cars (either from the car's console, smartphone app, or Tesla Account on the website).
Though, based on past experience with major software updates, anyone that hasn't yet seen the navigation update should wait for 1 or 2 months before getting concerned, since Tesla usually goes through a start-stop-resume distribution process, fixing major bugs, which usually means some cars may not get new features for quite a while.
