1.00 necessarily doesn't mean finished. But it's kind of like the line of the Base Game/Content having being mostly finished. At least that's kind of the usual note.
But i have a feeling that even IF 1.00 would be reached. There'd still be a lot more to come. Seeing as this is a huge project Technobrake works on. So i'd assume, if correctly, that this will take an abundant amount of time and the number versions may not mean much other then an updated version, for the most part.
So i'd take the idea of number versions with as much grain of insecurity to it's completion ratio or/and release as much as possible. Doubtfully this might not even reached completion much less release, by the time he reaches even 1.00, if not far above that. I get the feeling that NPRI might not be released on DLSite for the time being if not ever. If the Project is going to be rather impressive and very much sizeable. Since DLSite doesn't have Early Access or whatever shite people produce, on there. Although they do sell DLC for some products. Such as Goblin Burrow.
This is just pure guesswork, though.