Disney's Wreck-It Ralph 2: Ralph Breaks the Internet provides audiences another adventure filled with Ralph and Vanellope's antics. As most Disney films are known for, this sequel had a happy ending, even though the two best friends did decide to separate forever in a heart wrenching twist. Vanellope became enraptured with the online world of Slaughter Race, and is adopted from her former arcade game Sugar Rush into this intense internet multiplayer racing game.
This ending works in the world of cinema. However, in real life, Vanellope's switch from Sugar Rush to Slaughter Race might actually end really terribly for her. As Tumblr user megazeo points out in their post, the appearance of a character from a different franchise in the game code would be a major red flag for the creators of Slaughter Race. Vanellope would be assumed to be a gamer's mod at first, then a hacking prank, and then she'd be purged from the code to avoid any potential lawsuits. Vanellope's happy ending would not last long, and her character would be immediately removed from the game.
This seems harsh, but it is precisely what would happen in real life. At the very least, the Slaughter Race team would be looking at a cease and desist to start with as the creators of fan games routinely do. A reference might be okay, but a central character -- especially a popular one like Vanellope was said to be -- would be too much of a red flag to risk keeping in the game. Removing her would be a better move than keeping her and putting the whole company at stake.
The Tumblr post proves to be further viable in that it plays within the rulebook that the Wreck-It Ralph world has established for itself. The characters' actions have consequences even beyond their games -- after all, Ralph nearly got his game shut down in the first movie because he wasn't there when they needed him. Vanellope resisting her player in the second movie was what led to the central problem of the plot. The characters live in their own world, but that world is closely tied to the real world.
Unlike Q*bert and company hopping in a bonus level of Fix-It Felix at the end of Wreck-It Ralph, Vanellope guest-starring in Slaughter Race is much more visible. Q*bert and his friends only appear in Mr. Litwak's Wreck-It Ralph game in one arcade, whereas Vanellope moved to an online game available to anyone on the internet. Such an aberration would become noticeable quickly, causing the gamemakers to pull the plug on her character.
Despite Wreck-It Ralph 2's seemingly feel-good ending, Vanellope electing to stay in Slaughter Race just won't end well for her. Whether from real-world logic or the rules of the Wreck-It Ralph universe, game-jumping doesn't work. A server purge would endanger everyone in the game, not just Vanellope. Going Turbo and game-jumping was pitched as one of the worst things to do in the first movie, and may still hold true in the second movie. The only difference is that the film ends before we can see the inevitable end result.