Thank you for the share.
I found its mention of "our latest quality improvements to featured snippets" eye-opening.
They keep emphasizing "sources that demonstrate expertise, authoritativeness, and trustworthiness."
I suspect that the more they repeat those terms, the deeper they ingrain into their algorithm.
The helpful content update we've just gone through is probably only the tip of the iceberg.
There probably will be many tweaks from now on.
Although SEO Roundtable has shown how ridiculous some search results look in the wake of the latest update, I think it's safe to say that Google being Google, the quality will improve quickly once the dust settles.