The original writers of Total Drama Island originally wanted to return with season two under the name, Total Drama Reloaded, (now formally known as Total Drama Revenge of the Island), however, had to push that back to season four once seasons two and three were given completely different writers, hence why Action and World Tour weren't nearly as successful. To this very date, Island and Revenge of the Island are the highest rated seasons by critics and fans, making the team over at Fresh TV realize that keeping the island setting was a much better premise than a film lot or anything else.
In Total Drama Reloaded, Scott was supposed to be paired up with Molly, (Dawn's original name before the cast's final changes), but this was scrapped for unknown reasons, along with Scott's originally backstory, which was rather tragic. These were the original designs:
[img][800:1236]http://img3.wikia.nocookie.net/__cb20100928190129/totaldramaisland/images/b/bc/TotalDramaReloadedTDIBlogCharacters.PNG[/img]
Duncney breaking-up was a "network request" because writers wanted to give the viewers the idea that not all relationships last, and how they didn't want the show to become too "lovey dovey."