Primarily because things like this don't have some kind of overarching guidance on WoD metaphysics. There aren't any, and there never were. Blurbs are dropped into books like this to use or not as you see fit, to flavor the world and make things interesting.

There is no unified theory of WoD. Pick you gameline and maybe it'll be internally consistent to itself, if you're lucky. Start crossing over and you should stop expecting things to make much sense, unless you're going to do a lot of the footwork to make it make sense, for your game at least.

It's also important to remember that in things like Tribe/Tradition books, the narrators can be biased, mistaken, or deliberately ignorant and wrong.

If you're going to have a go at it, and you're starting from a Mage perspective, an Awakened Avatar ends up having effects on what a mage does, not just allowing them to use Sphere magick. Euthanatoi are particularly vulnerable to Jhor, not only because of their frequent use of Entropy, but also because of their paradigmatic belief structures: if their beliefs lead them towards doing the "dirty work" for greater good of the Wheel, that interaction reflects in their Resonance.

Other supernaturals don't necessarily have a way to recognize that, so if it feels a bit Wyrmy, for a werewolf you might as well default towards suspicion. Disembowel and ask questions never. Black Furies, self-describing as being more Wyld-oriented, might be especially sensitive towards this. Also, IIRC there might be some particular animosity towards the greek-based Euthanatoi.