There are 3 different scripts for season 2. The 3rd script is what ended up being used.
Gold Squad is based off of a different series called "Misfits: An Unlikely Team". Misfits was being written in early 2015, but was scrapped due to a lack of motivation. A year later, in early 2016, Gold Squad began production. The series featured very similar features. For instance, there was a squad of three idiots, just like Gold Squad. Jet was the main character and was very similar to King, Heavy was a character that was very similar to Scout, and finally, there was Dingo, who was very similar to Backlash.
Master Chief, the main character of the Halo games, was supposed to be a central character throughout the third season. Originally, season 2 was going to focus on Gold Squad trying to find Master Chief and at the very end of the season finale, they would finally find him. Throughout season 3, Master Chief was going to be working alongside Gold Squad as they try to take down Hemrix. For obvious reasons, Dylan decided to not go with this plot line and instead chose a more grounded story.
Due to some drama behind the scenes, the voice actor for Backlash quit right before production on season 3. Dylan scrambled to find a new voice actor. The voice actor for Vexus came up last second and voiced Backlash for the entirety of season 3.
In the opening to episode 7 of season 3, Scout is seen watching a show that was also filmed in Halo 5. This show is actually a show that the voice actor for Scout, Elijah Lucio, had created over a year before that episode aired. It was a show called "The Island" and lasted 5 episodes until it was canceled. This easter egg was put in by Dylan simply just as an inside joke.