Apparently if you started the BFA tailoring quests and have not completed them you cannot access Chromie for the anniversary quests. abandoning any active tailoring quest does not resolve this issue.
I have zero plans on completing the tailoring quest line, how do I reset my character so they can participate in the anniversary raids, let alone turn the quest into Chromie
You cannot. It only takes a few minutes to get through the quest to unphase the Caverns. Did it yesterday on two different Tailors. Click a few glowy blobs, kill a few trash, done.
Generally it is best not to try to solve phasing issues with the Abandon button. Your phase is changed when you accept the quest, and changed back when you complete it, not when you abandon it. So abandoning usually just means you risk forgetting why you are phased.
I am on the same issue and I will try that when I get home from work!