To that I would say the G-force strength and direction should be predictable, known even when they are designing the seats before building the rocket. So the passengers should be in an optimal position where they don't need to hold up their heads against the Gs but are cradled by the seat. I think that is very different from the bobsled analogy where the G-forces are changing intensity and direction all the time and you are not in an optimal position.

If the G-forces are unpredictable, well something went really really wrong.

But you are probably right in that there will be more medical restrictions than there are now. But someone with a spinal injury, or who is very pregnant, or very weak from age probably isn't going to be flying in today's aircraft either.