Amazon listings disappearing when Amazon goes out of stock?

In the last week I have noticed a glitch (or is it?) in Amazon listings. It started with 21309, when Amazon got it in stock my listing disappeared off the site. In my inventory the link to the listing is broken and it doesn't display the lowest price available anymore - it looks like what my inventory shows when I am out of stock, except I do have it in stock. This happened once before, but then the listing was eventually fixed. This time when Amazon went out of stock, the listing didn't come back. No big deal on that one as my listing price is super high and I'm not looking to move them any time soon. But...

Today I noticed it on two more listings - Eiffel Tower and Cargo Train 60052. Amazon went out of stock of Cargo Train 60052 and it looks like they just deleted all 60052 listings. It still shows in my inventory, but the link to the listing returns a "missing" result and if you search for Lego 60052 or Lego cargo train the closest you get to finding the set on Amazon is combo pack. With Eiffel Tower, there are multiple listings but the main one that used to show up when you searched "LEGO Eiffel Tower 21019" is just gone.

Anyone have any insight into what is going on here? I'm not necessarily looking to flip Eiffel Towers and Cargo Trains any time soon, but if Amazon going out of stock means they start taking everyone's listings down, that could become a problem.