Hey, a joint would be cool too
I totally get where you're coming from with the Augment rune and I would agree this could be a sign of .2 being the last major raid tier, but I would only stop there. 10.3 could be a bridge patch -> what's the come next.
I'm imagining it like this..
10.2 is the last raid tier.. and to bridge the gap between a potential (2025) release date they are releasing 10.3 which includes Avaloren, some new story, beginning phases of a world revamp & a new mega infinite dungeon (Uldaz). This would make sense with the item referencing Uldaz, & how "Avaloren" was conceptually introduced at the start of Dragonflight, finally bridging the story -> world revamp (11.0) -> conflict w/ Irikidon & Xal.
This gives them the extra time they need to fulfil the wishes of a world revamp, while also not having a huge content drought, maybe even world quests throughout the world start popping up during 10.3 & the bridge to 11.0 makes it worthwhile.