I originally installed Sublime text on Ubuntu 16.04 with these commands fall 2016:
sudo add-apt-repository ppa:webupd8team/sublime-text-3
sudo apt-get update
sudo apt-get install sublime-text-installer
sudo apt-get install sublime-text
How do I upgrade Sublime text to the new version 3143? Do I have to wait for webupd8team to update their channel? It seems unsafe that we should rely on external channels for distribution of the program …
There is a list of Official Repositories with instructions linked off of the Download Page.
I don’t use a Linux distro that uses any of those sorts of packages (I just slum it in tarball land), but you probably want to remove the existing repository if you’re going to use one of the official ones to make sure that you’re sourcing things from the correct place. That may or may not involve a package uninstall, but Sublime keeps your configuration in ~/.config/ which should remain untouched even if you uninstall it.
You also want to watch for which of the repositories to use; in particular the builds in the Dev channel require a license to use and are more “bleeding edge”, while the stable channel is more stable but updates less frequently.
webupd8team is an unauthorized distributor of Sublime Text. You should definitely remove that repo/ppa and use the official apt repo instead.
Thanks @OdatNurd and @wbond: I deleted the webupd8team repo/ppa from my sources.list.d, and following the instructions at the Official Repositories you linked to, I am now writing this in version 3.0, Build 3143 
It seem like some default file associations were lost during the update, but that’s a minor issue, and easily fixed.
Thanks!
My previous versions had been installed both by downloading .deb files, and (I assume) using webupd8team PPA.
I did an extra step to pick the latest version:
I just updated to the new version 3.1 (Build 3170) with these two commands:
sudo apt-get update
sudo apt-get install sublime-textI know this is an older post, but a much better alternative is here, including instructions on how to avoid versions from other repos (like webupd8team) and always prefer the official version of the sublime-text update (regardless of weird versioning schemes, outdated versions, etc.):
Thanks for sharing. I won’t add it to my Ubuntu installation right now, but will test your solution if Sublime Text doesn’t automatically update to latest stable version, when the next one is released.