[Miki1988]

Zeo didn't do great in ratings and Turbo made things even worse. PRiS was imagined as a sequel to Turbo and originally as the final season of the series. It was also treated as such since Justin and Adam came back as Blue Turbo and MM Black respectively. The season did have a Ranger character who had his own "lost sister" plot, which was treated in a way so it appeared that it was something that was going on even before the events in MMPR started to take place, thus setting up the idea of existent, never-seen-before PR teams outside Earth and our Galaxy (besides the Gold Zeo Ranger, the Alien Rangers and the Phantom Ranger). It introduced many new ideas and concepts for the series while staying faithful to what came before all the way back to MMPR S1. Hence why C2D had such a big impact to the then-past 6 years - it was time to say goodbye to the villains that were a part of the franchise the whole time - and it was meant to end the show. The producers did a great job making as many monster and villain suits available for filming at the time. They did plan out a big series finale and of course, you want the voice actors available when it's time to do a certain episode, especially if the episode is meant to be a 2-paer series finale. Now I'm not sure if they pre-planned the voice actors for the actual 2-part episode, but they did end up having the villains in the first 2 episodes of the season, so I think there's a good chance that some pre-planning was done (or at least the idea of it).

However, PRiS ended up increasing the ratings and eventually saved Power Rangers from cancellation. Which is why we all saw a stowaway sneaking onto a space colony the next season.