You could compare your list with a List of games no longer available on Steam or import your list at Barter.vg where such titles will get an automatic tag as "Delisted" or "Purchase disabled". Here is an example.
5 years ago
PermalinkDisplaying 1 to 2
Closed 4 years ago.
Found a word pad file from 2k15 with many bundle games. I know some may are Deleted steam store games just want to know if there is any way to know wich games are deleted, instead of search 1by1..
The list is here
https://www.steamtrades.com/trade/lQb1o/h-bundle-leftovers-recovered-txt-file-saved-of-2015-w-gems-keys-pp