Ossian Grr aka "Josh"
Josh, I think it's because it can lead to insecurity about whether or not you missed something in the rules. If I see that the rules sometimes say add 4 noise tokens and sometimes say to fill up the noise tokens, I might wonder if I missed a rule somewhere. They seem like they mean the same thing, yet the rulebook author chose to word them in different ways in some places. That could mean that they really don't mean the same thing and I have a misunderstanding about something.
It's just always better if rule authors decide on consistent wordings to avoid any kind of confusion.
See my comment above.
They mean the same thing now... but the wording leaves the door open for them to mean something different (i.e. an expansion location that has 5 or more Noise Token slots).