Actually it happens with all bundles. Or at least, most.

If anyone wants to know what's the difference with this bundle and the one in Steam (Anomaly Game Collection iirc) is the soundtrack for Anomaly 2. This bundle has it, while it has been retired from Steam and it's not available anymore. Both bundles have all Anomaly games.

It happens with all bundles and DLCs, AFAIK Steamgifts just can't recognize that, just if you have base game for DLCs.
Also Steam stores all apps and packages info even after "deleting" it and you can still see on SteamDB