https://www.slashfilm.com/mandaloria...uide-canceled/
It's unclear at this point why exactly, it might be because of the Gina thing but the closest we have to an official explanation is the series is 'ongoing' so they'd have to continue publishing new versions practically every year. (The already published tie-in books however mostly say "season one" on them so I'm not sure why they couldn't do something like that). A novel would be even easier to not involve Gina, but that's only speculation without knowing what it was about exactly.