That very well could be the plot to whatever the 5th game is going to be called. I was watching angry joe's review on Saints Row 4 and he said it was pretty fun, even for how wacky it is and he read somewhere that the 4th is going to be the last of the, forgive me for using this word, ridiculousness. Next gen Saints Row might just be pretty good.

Here is a quote from the design director.

"We're definitely considering Saints Row IV sort of the end of that saga of this character and the Saints as they are. So if there's any more future Saints Rows - which you know we always hope there will be, we hope there's fans for future games like that - they will probably continue in a different direction."