Ubuntu Pro only provides additional updates, it still provides updates for the APT software you already have. From what I could gather, all it adds is longer LTS support and a few antivirus packages. So no need to worry- for now at least.
Ubuntu Linux
Linux for Human Beings.
Ubuntu is a popular Linux operating system for PC / mobile devices, etc.
Developed by Canonical & based on Debian (another older Linux OS) which is known for it's rock solid stability.
Ubuntu is trusted everywhere computing by professionals and common users alike.
Ubuntu Pro is free.
My understanding (and I'm happy to be corrected) is that feature and security updates will continue to be provided for Ubuntu.
Ubuntu Pro's update badgering seems to allow for updates to be provided for packages that aren't part of the base distro makeup - like packages that are held in non-Canonical repos.
For home users, Ubuntu Pro is free... for now.
I don't think it's anything horrendously bad, but the way it's been rolled out is pretty fuckin' far from good too.
This is correct. There's no need for Ubuntu Pro to get the updates you used to get prior to Ubuntu Pro's introduction. Ubuntu Pro gives additional updates that were not available before and the community does not provide. It's free for up to 5 machines so you should register and enable it. There's no downside for now.