Originally Posted by Saibak
- extend the anime to 24 episodes
- go for a second season after case #X
- change the ending (Monokuma confuses the punish-all-button with the execute-the-murderer-only-button)
Extending the season or getting a second season usually is not the studio's decision. They're just paid by whoever does own the rights to the anime to get it done.
Take the Fate/Stay Night anime, which was animated by DEEN. Recently there was a Heaven's Feel adaptation confirmed to be animated by ufotable. Had DEEN actually had the rights to the anime, ufotable shouldn't be allowed to make any anime for the franchise.