I mean, ignoring the fact of how stupid it is that she thinks it's not real.
Yeah, FOG is actually a double-edged sword. It's tricky not to overdo it in VR, as it could take away from the impact irl. Players could feel like you are just recycling the same themes.
I'm also wondering if Liz or Leafa ends up somehow having sex with Kirito one time, and that one time is "enough" to trigger whatever pregnancy status, or thing that starts whatever it is. And then I wonder if after that point because Kirito thinks he made a mistake, he ends up further alienating himself from Asuna and things go further south for him.
The more obvious side is probably Inoda and Asuna end up triggering the pregnant status, and honestly I kind of find the idea hilarious when I think about it in terms of it happening in FOG. I don't know what Asuna would do to try hide the status, or lie about it, but I find it kind of potentially interesting how in "one world" she'll have a pregnant status, but in "another world" she'll be completely free from it. So the balance between having the status in-game and being normal IRL, just seems interesting.
But yeah, it's probably more possible that this pregnancy/kid update thing Fujino is doing could cause issues. The goal is to evenutally have a lot of stuff transition to IRL, and we would probably appreciate it more, since there's more places to explore. Speaking of places to explore, the brothel is actually open in IRL, so I'm curious and excited what might happen in the distant future.