If you try a site command on Google News right now, you will be out of luck. Zero, no, results will be found or returned. This is a bug that Google has acknowledged and Google will fix it "in 2020." When in 2020, I do not know, but it will be fixed in 2020.
Pauline from Google posted this news in the Google News Publisher Help forums earlier this month. It has not been working for a couple of weeks now. Pauline wrote:
Hi everyone,The site search functionality is currently not available on the Google News app & website. The Google News team is working on bringing this feature back in 2020.
To verify if your content has been indexed for possible display in news results, perform a site: search in the News tab of Search. This special search operator mode will show all content from your site that has been indexed by Google. This content might appear in news results if it meets our news content policies.
Thank you.
So instead of going to news.google.com and doing this:
Go to google.com, type your site command, click on the news tab, and you will get this:
The issue here is this shows all content, web and news, and is not limited to just news content.
Why did this happen? I suspect it happened when Google revamped how Google News gets content from not just the Google News approved index but the wider web. See how this all falls into place and then Google has to pick up pieces that were overlooked either on purpose to launch it by a certain date or by accident?
Forum discussion at Twitter & Google News Publisher Help.