I have a couple of problems with your suggestion, first - upgrading a system as a background task is generally seen as a bad idea because it gives you less control over what happens, and second - your way of doing it triggers the upgrade only at boot time, if you really-really want it to happen automatically maybe you should let cron (and anacron) take care of it and do it once per day, or once per week. Just my opinion, users are free to do whatever they want, of course.
I have run [and still do] Debian servers for many years using crond to update them automatically, usually on Monday mornings. It works great.
I would not run it at boot for several reasons and certainly would not recommend it for a newbie with no understanding of what is happening.
Of course, it is all about choice so thats why we discuss options rather than all follow one path.
Servers and desktops are different animals in many ways. Normally only experienced folks run servers and desktops are often run by folks who just want an environment to get their work done with the least overhead of skull sweat [thinking about it].
The true power and joy of Linux in general is the fact that there are choices and options for any use and skill level.
Nnew folks would be well served by going slowly in the command line until they understand what is going on under the hood a little before blindly changing system behavior as it may yield unexpected results.
THe folks that maintane this distro seem to be pretty solid on not busting stuff with updates. However, these are complex systems with no way to test every possible configuration before adding an update.
You would hate to wake up some morning with a bunch of mission critical email or document preparation
on your plate only to boot your computer, watch it update then find out your mission critical email / browser / word processor somehow stopped working because of an update.
And you promised your boss to have it dealt with before the office opens at 8. Just as ferinstance.
Letting updates propogate awhile might be best for those that just need it to work. Keep an eye on the forum for problems then update.
Its not always best to be "first". Not to scare anyone off but its good to discuss these things.
Might check out that update notifier thing too.
Just my thoughts before much coffee.