As I understand it...
The text message that the character NosyFellow sends is at the end of the current game content. When more content is released in future version the current messages on the routes that are extended will be replaced with a new message and the new end of content.
If you mean after the next update, I've been saving the "save" and "timeline" directors that are located at
"C:\Users\<userid>\AppData\LocalLow\NosyFellow\NTRMobile" to another directory. I have multiple sets of them depending on what I'm going for (Low Lust Lovers route, NTRS/Happy, etc.). When you want to continue you can replace the AppData "save" and "timeline" directories with the saved ones. Do Be Aware that you are messing with files in Windows-controlled directories.
If you mean for other routes (like Loves vs Happy) then yeah you have to make different choices. Just save the directories above, if you want to, and then do the "Factory Reset" in the Settings.
Yamakh in a previous message posted this very helpful guide. It says V0.24.1 but it has through V0.24.3: