As of today, google's "request indexing" feature is back. https://twitter.com/i/web/status/1341437011618623496
I went gung-ho and after about 10 submissions I got: Quota Exceeded Sorry--we couldn't process this request because you've exceeded your daily quota. Please try submitting this again tomorrow. Has it always been that way?
From a couple hours to a few days, provided the page complies to their ToU. I actually had pages re-indexed within minutes.
I think Google is done with their rolling updates of the core algorithm and will impact the websites immediately in the organic search rankings. I wonder what's the big next for Google.