Google's John Mueller said on Twitter that there is no specific timeframe for when an out of stock product page on your e-commerce site will end up resulting in a soft 404 in Google Search.
A soft 404 is when Google thinks a page should return a 404 server status code but technically is not. Google has said that product pages that are out of stock should likely return a 404 status code. And Google has also said that if it does not, Google will likely soft 404 those pages anyway.
John said in November 2020 "out-of-stock or not available pages generally tend to end up as soft 404 pages. And when they go into soft 404 state then the landing page disappears from search and with that the image is also kind of lost."
I asked John if there were any timelines around when an out of stock product page would be soft 404ed. Like if a product goes out of stock on the 10th of the month and Google discovers it on the 11th, does it take a few crawls, does it take a month? John said there is no fixed time. He also said he does not think there were any changes to how Google reports on these soft 404s in Google Search Console with the recent coverage report change.
Here is John's response on Twitter:
There's no fixed timeframe, and I'm not aware of any specific changes there recently (though I know people are always working on improving our soft-404 handling). If there were recent changes, they would be unrelated to any reporting in Search Console.
— 🍌 John 🍌 (@JohnMu) January 14, 2021
Forum discussion at Twitter.