As far as I know the Ohio Scientific Challenger 1p is also protected from 'non-existance' by the apparent non-existance of a time machine, and persistent longevity of the earth.
But I don't think this is a 'future' just a 'past'.
That's why I surprised myself by selecting PPC + OS 4.
The rest seemed like retro - as unlikely as PPC + OS 4 is, PPC is still alive - with new CPU's being released, and OS 4 - the same.
Oh don't get me wrong, I almost picked 'no future', but, that's not quite true yet. it may not have much of a future, it may be a sick one - but it's not played out yet.