It’s not known yet why all of Rockstars games suddenly disappeared off the platform, but as a result, there was undoubtedly quite the rush to get their library back to its full majesty as this slip up managed to sneak in.
In the confusion, Midnight Club 2 briefly appeared back on the storefront for around an hour, with the player count spiking to 40, as players rushed back to the title, with a few Steam reviews popping up for good measure.
Midnight Club 2 was originally pulled from Steam due to song licences that were set to expire. Rather than renew these deals, it was much easier to simply delist the title and stop it from being sold, with the title being hard to track down ever since.
Currently, the only way you can actually look at the title is through a web search or handy link, as since being delisted, the Steam client does its best to hide it from view.