Observable Universe from two different perspectives My layman understanding is that the universe is much bigger than that we can observe however due to the cosmological constant the observable universe is the matter etc. that is not moving away from us at a speed faster than light.
It is said that we can never reach matter outside the observable universe which leads me to the following paradox; imagine two people are placed at galaxy A & B in the below diagram:

The two circle's indicated are the observable universe from their own perspective, A can never reach B as he is moving away from him faster than light and vice versa. A and B can however reach C, so they both decide to go there to meet up.
My question is would they ever actually reach each other?
From my research I know (without understanding the maths) that even moving towards each other at 0.99c they will still only move towards each other at say 0.9999C (basically never above light speed) but it seems that matter from outside their observable universe could reach them.
I have tried to find an answer and found that perhaps when A and B get to C their home universes have now moved away so that neither could ever get home (which means A will never see B's home galaxy and vice versa) but this still doesn't explain how A could reach B (if it even can).
I may be misunderstanding the expansion / observable universe but from what I have read the above logic (A never reaches B) should be correct?
 A: Yes they can meet.
Assuming your diagram has the first circle as all the events that A can reach and the second circle is all the events that B can reach and assuming event C is in the intersection then A and B can meet there.
They can't necessarily "decide" to meet there of waiting for bilateral communicate before you head out makes it so they can't both reach C.
Keep in mind the essential difference between things that can affect you and things you can affect.
If C is in the interaction of things A can affect and things B can affect, then both can affect C.
This is normal. When you look out far away you will see thibgs that you can affect but some of the thibgs that affect it are not things you can affect. This already happens in Special Relativity. Two spacelike separated events can sometimes affect the same event but not each other.
Now if you are a moving observer, then observer A originally at event A could meet observer B originally at event B. And then they can shake hands at event C even though the event A and event B were separated because it is the observers A and B affecting each other, neither is going back in time to change event A or event B.
Which is back to first point, they can't decide to meet up. When they meet up that decision (those two independent decisions) to go to C is/are in the causal past and so already happened.
There isn't a big mystery. When you travel north you can meet someone that was traveling south. If your cars could only go an hour's drive you could thus meet someone that lives 2 hours drive away. Nothing spooky is going on in the slightest and this is totally normal.
No. They can not meet.
Assuming your diagram has the first circle as all the events that can reach observer A and the second circle is all the events that can reach observer B.
Then if A is not in the right circle and B is not in the left circle then there is no place and no way they can meet. By definition.
