Marcus Stephenson of 2K Sports has confirmed on Twitter that the newly released PC version of the WWE 2K15 video game allows for fan modification (or "mods/modding") of the game. The ability to examine and tinker with the game files is an increasingly important aspect of PC gaming, both to mess around and to try to improve the overall experience. The latter is a big deal for a game like this, which has gotten mixed reviews. In this case, players quickly got deep into the game files, but it took a day or so after release for 2K to officially acknowledge and endorse the modders.
2K has set up a modding subforum of the game's official forum on their website. As seen in the video embedded below, where audio of the fans singing "John Cena sucks" has been added to Cena's in-game entrance, entrances have already been successfully modded, with music and Titantron videos easy to replace. Another video shows Seth Rollins' music, Titantron video, and "minitron" video all updated, while yet another shows an updated entrance for Sheamus.
The game has only been out a couple days, so expect a lot more where this came from.