[Moderator note (bmah): The initial 37 posts in this thread were moved from a discussion of software 2018.6.1.]
Don't call Tesla to push an update. Unless you have a major issue that you know is fixed later, or your version is ridiculously old.
Most people are still on 17.50.2 or 17.50.3. There is no reason to nag them yet. It's understandable they don't want 27277371 phones a day at every SC asking for an update.
Unfortunately, it is possible for cars to fail to update, without any notification to the owner that this has happened.
Our S 100D received the latest update yesterday - without any notification to my smartphone app that the update was available or that the update had installed. However, our S P85 did generate notifications about yesterday's update.
Our S 100D failed to install an update last fall (while it was stored in a public multistory garage during Harvey). When we got the car back, I noticed we weren't receiving updates when many others reported online their cars had been updated. I called Tesla - they looked at the car's logs and found updates had been pushed to the car and failed multiple times, and our car had been moved to a "do not send updates" list on the server, and that we'd have to take the car to the local Service Center before any updates would be sent to the car. This happened without any notifications to our smartphone app or on the car's onboard console. If we hadn't called Tesla, we wouldn't have known about this, and wouldn't have received an update until the next service visit.
Only Tesla knows the algorithm they are using for the order and frequency of release distribution to their cars, so customers are left guessing as to when they'll receive the next release or if their car is having some problem receiving updates (which might be due to home networking issues - and not even in the car).
One way for Tesla to know this is an issue is by having customers contact customer support to determine the status of updates for their cars. If a car hasn't seen an update for 3 months or longer, it's not unreasonable to place a call and verify there isn't a problem distributing an update.
But, probably not worth contacting them sooner than that, since even if Tesla pushes a major update to every car, it can take several months for that update to be distributed to all cars.