Diving into the Ynnari, my initial impression was the the HQ auras of the various Aeldari factions would overlap to other Aeldari units. For instance, the -1 wound aura that a shadowseer would normally grant <masque> infantry would extend to a unit of Ynnari wraithblades.
I swear the playtesters on the Splintermind Podcast discussed it as if that were the case too (I need to go back and re-listen), but re-reading the rules it seems pretty cut and dry that it doesn't work that way.
Everything in a Ynnari detachment does get the Ynnari keyword and thus can benefit from all the stratagems, psychic powers, relics, and warlord traits, but that has nothing to do with their auras.
The relevant bit for the auras is "In addition, all Ynnari units replace every instance of <craftworld>, <kabal>, <wych cult>, and <masque> on their data sheet with the appropriate keyword from the table below.
<wych cult>=Reborn Drukhari
It seems clear from this that the only aura sharing this opens up is succubi granting re-roll 1s to Kabal units, and archons granting re-roll 1s to wych units.
Am I missing something?