There is no way to view out of stock variations and there really needs to be. This is a feature that has been requested for years, but I haven't seen eBay offer any updates.
Currently there are 2 ways to see out of stock variations- the first is to check your orders page. If you scroll down recent orders you will see quantity such as 1 (0 available) indicating that the buyer purchased 1 and you now have 0 left. That's the easiest way to keep up with it if you can. Of course when you have thousands of listings, it becomes much more difficult.
The other way is very labor-intensive- to a painful level when you have a lot of listings- and that's to go through your listings one by one. On your active listings page click on the link below each listing title that says- for example- [8 variations] and that will take you to a page that shows your stock- you can update the quantity from there without having to go into the listing to edit.
There is also no way to filter your listings to view only those with variations so you have to scroll through your entire active listings list page by page.
tyler@ebay- I copied the above text from an old post of mine. This is something you were working on with the Seller Hub team in 2019. Can you ask them if there are any updates- will we finally see this functionality this year?
