There is no way to know with absolute certainty, but we can sometimes predict if they will come back on the buy box.
The best way to go about this is to check the Keepa history. For example, if you see they are on the buy box for a few months, then off for a month, then back on for a few months, you can predict they will be coming back. You want to look at the past trends of the Keepa graph and see if you can notice any patterns. Then you'll use those patterns to predict if Amazon will come back on the buy box.
These patterns appear a lot with seasonal items like the one in the example below. Amazon seems to jump off the listing when it’s cold (since the item being looked at is a tube used in the summertime) then come back on when in the warmer months. So, if it was February now, I would avoid ordering this product even if Amazon wasn’t currently selling this item because they would most likely come back on the listing judging by the pattern.
Of course, this is not absolutely perfect, but it can help to give us a good idea if Amazon will be coming back on the listing or not.
If there is no visible pattern and Amazon was on the buy box in the past but hasn't been selling the product for a few months then I would consider starting out with a small order to test the waters. That way in the event Amazon does come back for whatever reason you aren't left with a substantial amount of inventory.
Will Amazon come back on the listing?
How to tell if Amazon will come back on the listing?
