It’s just another example of how powerful of a tool modding can be when it comes to helping games survive for a long time. It’s not the first time we’re seeing an example like this, and there are some even more extreme cases in the gaming industry.
It’s not rare for a game to continue being played for years after its release just because its players keep modding it and adding new features to its gameplay. Sometimes, these mods can evolve their own communities as well, eventually branching off into a separate game with its own unique features.
For now though, even the addition of new characters to “Super Smash Bros Brawl” is more than enough to keep the game alive and well, and as long as we have modders like these operating in the community, we should see the title enjoying its popular status for a lot more time to come, perhaps even after the next game in the series has been released.