I don't think this is the link you intended :-(
They way I recall it is that such a horizon does in fact exist in FRW cosmologies IF
the expansion of the universe is acclerating. (Current data suggests that this is the case). I suppose I should go look for some references to support my recollections.
If the expansion of the universe is deaccelerating, we will (again IIRC) see all of it eventually.