A tell-tell for the unattended-upgrades process

[Valtam]

Your opening statement from your first post was "I have a habit of performing updates via Synaptic". That very specific statement was addressed.
New people to linux won't even know what Synaptic is, let alone use it to perform Updates.

But let's suppose I had approached the forum this way:
  Hi. I am a new Linux Lite user. I like it very much.
  I began my session today by clicking on 'Install Updates'.
  A message appeared saying 'Linux Lite Updates have failed'.
  The log file says it couldn't get a lock or something.
  What's going on?

We have many threads where this kind of question is asked and a suitable solution is provided. The same goes for your Chrome hypothetical. The solution in any of those cases has never been "Would the response to either of these have been, try again tomorrow, try again in half an hour; maybe 15 minutes?"

As for "some kind of tell-tell were to appear somewhere on the screen to advise us when this process is underway", if you're using Synaptic and this happens, then let me refer once again to my second answer where I recommend the use of our application, Install Updates. It already has code in place to completely avoid this from happening and is the best solution.