There was an excellent phrase I wanted to pull out from another part of Martin Splitt's interview on passage indexing. Martin said at the 38:30ish mark that passage indexing is really a lifeline for pages that have good content on them but it is buried or diluted on a big page.
SEOs and folks who are watching this webinar or reading this blog, likely do not have to do anything. Passage indexing is for Google to better understand those poorly designed or structured pages. I discussed this before when John Mueller said something similar a few weeks ago on why you don't need to optimize for passage indexing.
Here is the video embed there:
Earlier in the video, at about 14:30 Martin said it might not launch before the feature freeze, it might not go live in 2020.
But he said a web site that already ranks well does not need to worry about this. This is only changing rankings for pages that do not rank well.
So again, well optimized pages should not really see a big change. Of course, if poorly optimized pages now out rank you - that will be felt. But what more can you do? Make your pages less optimized?
Forum discussion at Twitter.