While it's certainly technically true that it's just a 200GB SSD that could be used for any samples, opening up the ability to delete factory samples immediately creates some non-trivial problems. Most notably, if someone deletes samples they didn't intend to, or if they later find out they had presets that depend on these samples, or want to resell the instrument - then there would need to be a way to restore factory samples. I can imagine all kinds of restrictions on distributing 8dio's content that would prohibit this. Since 8dio doubtless owns the copyright to this content there isn't going to be an expiration date on that restriction (at least not in our lifetimes.)
Another approach would be replace the current SSD with a much larger one to open up much more user storage, but I'm sure that comes with its share of issues as well.