This quest in unavailable on my alt, completed on my main.
Yes I finished the campaign but I cannot get this quest to pop up. Yes I looked through the telescope etc
This pinnacle weekly quest is part of a mini-series that may cycle. Based on the pattern so far, they seem to go in this order:
Worldsoul → Archives → Delves
…and the order is specific to each character. So if you have the Worldsoul weekly available, that is your pinnacle weekly for the week on that character. Archives would come on the next reset after you complete it.
I’ve done the pinnacles in a scattered fashion on a few alts and their progression with this is all over the place, but it seems intended in order to not give the same character the same weekly repeated if they happen to miss a week or five.