Not necessarily. It only shows that Blizzard has determined that the item is an upgrade. We have to separate out the “combat upgrade” from the “moggability” (is that a word?) because with most things, they are intermingled. But with an item that provides no main stat for a spec, this option is not available.
So an upgrade is (apparently, according to Blizzard’s rules) something that has a main stat on it that matches the loot spec’s main stat, in the case where any main stat is present.
Again, I’m not saying it’s not a personal upgrade. I’m not saying this has no basis in common sense that people are going to want mogs. I’m only saying that, if we are going by the guidelines that Blizzard created, and that (some) people are expecting others to follow, it can be considered jerk-like behavior to go against this.
It’s not lost on me that if it takes this much analysis, interpretation, inference, etc. that it’s obviously not a clear set of rules lol.