I think what your saying is likely but a little unsatisfying. I think NTR the way its been and NTS need to diverge early on for their to be any meaning(See NTR Survival Z). Like whats the point in NTS if by the time you figure everything out shes fucking pregnant and has moved half way across the country. Also not to get into a semantic debate about NTS but I feel like you would need kirito encouraging asuna to cheat rather than him spying and figuring it out but just doing nothing to stop it(pretty sure by all definitions this is still NTR). I do agree though that the green bar might be for kiritos corroption rather than another for asuna. But then what would the story split be, if you go full suspicion and you find stuff out, your lewdness would be really low so would he even get off to the NTR. And then if you go max pervert he wouldn't even know its asuna assuming the red is for suspicion. And thats all assuming those choices are always going to affect one bar or the other. There could be four routes(Which would honestly make more sense with those bars), in which you have no bar run where both are low and your just a normal guy who's cucked and then there would be an actual NTS route where you both know its asuna and you get off to it(still doesn't fit my definition of NTS but whatever).
Also an open world is highly unlikely and would be hard but lets not forget fujino has but an insane amount of work into this game so far. Like 60 maps that look better than literally every other rpgm I've played on here and all that for an ntr walking sim, just saying its not out of the picture. Also has Fujino stated he wants to go back to monthly(wouldn't be surprised if wants to but I just haven't seen him say that from what I remember)? I think if I was fujino right now I would consider the fact that I just moved too a whole new country to develop a porn game(thats getting an official translation from saikey), in some ways, although I don't think fujino is the type to drag things out, he has all the incentive in the world to make this game take as long and have as much high quality content as possible. Not saying he will do this but once again its not out of the picture because right now he has no way of knowing if his games past sao will have as much appeal as this one.
I think the NTS and NTR are way more black and white than a blurred line between the two.
My guess is there are going to be actions that you can approach either with Kirito being suspiciouse of the actions or being turned on by it.
For example a phonecall and asuna sounds weird and you get the option to:
A. Ask what is going on. (which in turn increases suspicion)
B. Fantasies about what might be happening. (which increases lewdness)
I agree that there might be a third path where instead Kirito is neither being suspicouse enough or turned on enough by the end and will just stay obliviouse to everything. i don't think there will be a fourth option where you do neither.
I think there will be a harsh split between the two before asuna gets pregnent but still quite close to the end.
The 60 or so maps are most likely different dungeons, that tower that was mentioned and maybe even diffrent towns? maybe a hidden village too. My guess is that it's all related to a more involved gameplay system but with a linar "Main quest" in it, there is a fair chance for side-quests tho.
Fujino might not want to make monthly updates but looking at the comments on his patreon (whiles most are supportive) there is a fair chunk of japanese and chinese speaking supporters that appear to want more regular updates. Wheather or not he will do it, i have no idea but i do think that there is a chance for it.
The Patreon modle also dosn't lend itself that well to updates ever 2-3 month, why sub in a month that you are not getting anything anyways and instead just wait for the next month and then support again? (to support the creator and i would definitly do that but i doubt that everyone would think like that)