No SM group has ever done as well as ITZY has at debut yet they all eventually hit big so I don't think having such high expectations for a new group is appropriate. The likelihood of them releasing a hit as soon as they debut isn't very high, and it rarely ever happens with SM. As far as I'm aware, wasn't it only SNSD's debut that ended up being a hit? Everyone else flopped at debut.
Also, from what I know they won't promote together with the "human" members but will instead promote in an alternate universe so they will release separate MVs and performances. So if you follow EXO, it's like their X-EXO concept only this time their counterparts actually exist in the form of AIs which will have their own promotions. But there's still not a lot of info on this entire thing yet so I guess we'll find out more once SM actually makes their plans more clear. That said though, I doubt they would jump into a project they couldn't fund. Pushing aside the weird concept, this has HUGE potential to big a very big concept amongst kids and anime/gamer fans who are exposed to this more often. If they end up promoting this properly, this concept has potential to be huge money makers. Especially if they expand on the AI counterparts and make merch, games, comics/webtoons etc.
So leaving aside the fact that it's a weird concept for K-POP fans since we aren't used to stuff like this, from a business perspective this is probably one of LSM's most genius ideas lol. It really just depends on how they promote it.