The deve will replace all art stily like the dev of Defenestration doing. Replace all art don't mean do another game but rplace the arts making all beetter. It still on Dev to decide.
this game is just in "On Hold" that all.
Still, the saves we currently have probably won't be valid in an entire new build right? So there isn't much reason to play this even if people manage to get it working. Also the dev said it'll be released "this year" so probably December if we're lucky (not targeted, just tempering expectations). Also saw patreons got a chance to request things for the rebuild, I hope they made good choices.
I suppose the real question is: should this actually be listed as abandoned so the rebuild gets a fresh page (assuming it ends up here, fingers crossed)? Unless when you rejected the other person, you were implying that the old version will still be getting updates.
Not sure where you got replace all the art from, the main idea of what is happening to Non Monstrum is being referred to a rewrite. The author explained that the idea behind Non Monstrum and the world 'Ealia' changed a lot since it was first released almost half a decade ago. So after the release of chapter 2, the author felt how uncomplete chapter 1 was, and how it could be better.
So the creator decided to rewrite chapter 1 for a final time and also expand it, change a few character details, and also make sure that it all has art, since now they have the money(for now at least).
Though I don't consider it a different game, or abandoned. Nowadays a game can be totally different from how it started, Stellaris 3.0.0 is totally different from Stellaris 1.0.0, but people never stopped saying it is Stellaris. Nowadays in the internet era, things will sometimes evolve and change, sometimes for the better or worse. So it will still Non Monstrum, just reformed