If you troll around in "New" for long enough you'll see threads where some version of this happens - though it's impossible to tell of they are bought upvotes, fake accounts made by the poster, or just friends that were asked to come and post. You'll see some mediocre SaaS thing that's posted here and on Product hunt and a bunch of comments from new users like "Wow so exciting, great job!". They usually get flagged quickly. I have never seen something that I felt was suspect that didn't fall into the really blatant category, so either these guys are really good, or they suck.

It would be fun to use chatgpt to make some throwaway SaaS mvp and then get these guys to promote it to see what the experience is like (and then write it up for HN).