The person I replied to specifically said
Therefore, in technical discussions, I use the word "Linux" to refer to the OS, as "this software is compatible with Linux". But, when I want to stress out software freedom, given a large influence of the GNU project, I say "GNU/Linux".
So they use GNU/Linux to refer to any open system
There’s wear and tear on your drives and your bandwidth usage, but if you meant from the tracker’s perspective - none, in fact the more the better