That argument is all 'smoke and mirrors' IMO. Look at it this way. The Earth is moving in its orbit far faster than the pedestrians are walking. So when the Earth is moving in its orbit (generally) away from Andromeda the race hasn't evolved yet while when the Earth is moving toward Andromeda they should have already conquered us.
Any information about simultanaity can only travel at the speed of light. So I think you have to restrict the 'plane of simutanaity' to local events.