google can't tell a peach from a watermelon, so I doubt it will ever be able to know if it's machine, or human generated content. To "know" if the content is machine / human generated it relies on users feedback and actions, so if the software creates human readable content google will suck it... which they do anyway cause I've heard them say that they hate content generating software. Don't ask me for a source for this statement cause I don't have it. All I know is that I've read it somewhere (possibly on this forum since I spend most of my time on here) and that's that!
This being said, here are the answers to your questions (from MY point of view / experience, obviously, since I can't speak for everyone)....
1. no, google can't tell now or in the future if it's machine-generated content. Again, if the users reading this content behave the way the googlebot is programmed to interpret human behavior it will label the content as poor quality and "penalize" you with loss of traffic and/or rankings. But they (google) will never be able to understand if it's machine generated content, or written by yourself. And if the software you use creates excellent content that your site's visitors find useful then you churn content on autopilot and you will do just fine. And luckily, there are many content generation tools on the market today and they are getting better by the day, which I LOVE (I'm a passionate hater of google in particular, and of obscenely rich individuals and corporations in general)
2. lots of people DO generate the same type of content in the same niches, over and over again. And the content comes out as 100% unique all the time. So, no issue here
3. I do use content-generation software. I've been using Synthesis from prosperative.com (I don't think it's available anymore... not as standalone software anyway, it might be available with their monthly membership) for 2 autoblogs that I've set up last month and I'm letting the software autopost to those shitty autoblogs each day until they either get deindexed (they are indexed at the moment), or start ranking. I didn't do any on-page or off-page SEO for those websites, nor do they even look like websites, it's just a wall of text with my chosen keywords in the title and an affiliate banner at the top of the page. I'm sick and tired of playing google's retarded mind games, so I don't use image optimization plugins, I don't use use speed optimization plugins, I don't use CDN or SEO plugins, no legal pages for my website, no interlinking anywhere, no sub-headings and bullet points, not even a single image on the entire site. Just a 600-800 words article on each page and an affiliate banner. If this garbage content (most of the time it makes no sense, but I don't care) starts making me money (I've set my happy threshold at $200-300 per year in Clickbank commissions) behold 100 more autoblogs incoming next year. If it doesn't rank anywhere, at least I use up all of the credits that I have in my Synthesis software cause I tried using that content for money site but it's so bad that I literally have nothing to do with 5000 credits.
As filler content, this software-generated content is good. If you input broad keywords into the software... like "weight loss", or "dog training", or "virtual reality" or whatever you will get decent content that you can just slam on your money site as-is and without a problem. But when you try long tail keywords, or very specific keywords the software falls short.
Apart from Synthesis I am also testing Article Forge (which is 99% similar to Synthesis) but somehow, the quality of the content is better than Synthesis. And I also watched some Conversion.ai tutorials on youtube and the content is really impressive, but... it requires more manual interaction, but that's still good for most people, especially for those who hate writing or are not good at it, or don't have deep pockets to throw $2000 a month at academic writers to create pulitzer-winning content. My problem with Conversion.ai is that it's expensive as fuck ($109 per month is too much for a content-generating software, even if it's good)
So anyway, I don't use content generated by software on the sites that I care about, but I do use it on autoblogs and web 2.0s (for acquiring backlinks). And, like I said, if each autoblog makes me at least $200 per year with this type of content I will happily buy more credits and continue churning and burning until thing stops working. But for my money site I will not use software-generated content, not in the near future anyway because no software can yet compete with the human brain