If Google thinks a page has particularly bad page speed score ( they did NOT specify a number ) they might mark that page as not mobile friendly in SERP.
Google has a URL removal Feature in SC it's NOT advised that you use that when you are migrating from one URL to another. Redirecting the old to new is the best course of action for migration if the URL changes.
On desktop index content hidden within tabs will not be treated as primary content but with mobile first index all those content will be indexed and ranked as primary content. Obviously, they will try and figure out what content from those pages are relevant and good for users and treat them accordingly.
Google is now testing filters in recipe search. When clicking on a filter, you get an interface that shows: bigger expandable cards, bigger thumbnails, infinite scrolling.
Bing has followed Google’s lead and is now showing hotel amenities in the local knowledge panels, detailing the common amenities that many hotels have.
Google has made a new change to AMP reporting based on how critical they are.
From the end of January with Chrome 56, Chrome will mark HTTP sites that collect passwords or credit cards as non-secure. You can learn more about HTTPS here and find some tools related to HTTPS here. Google has also started warning Webmasters who might be impacted by this via Search Console.
Google might start to show price drops for products you might have researched in the past. Looks like a limited test for now but I can see a future where this is more common and of course it will be opened up for advertisers via Adwords.