Based off observation, the counter for the newly added games moves now and then. In the beginning it was in batches. A couple of hours ago it was going up one by one. If it wasn't added yet, if possible look for what was newly added and see where it landed or if you bought the bundle, use the search bar. There are also Google Sheets out there that also update now and then as well.
Good luck. Right now the count is 1,509.