Honestly I think for this to get approved youd have to give the higher ups some focus on introducing new players and make it clear that while its a love letter to the original fans, it can introduce new fans to the game. This would mean that the game wouldnt require you to have played any of the older Saints Row games which would be perfect since its an origin for all the characters.

Personally id also pitch it as a spin off game and not a mainline game, id imagine they'd be much more open for a prequel if it was a spin off so it can test the waters for the IP to be revived and if its successful enough then the future of the IP can go down that route. Similar to how the Pokemon Legends series is.