You can CERTAINLY gain an advantage knowing an opponent is about to NMR, how can someone claim otherwise??? If you know your neighbor/enemy is about to NMR, all units are about to hold...you know no supports are given, you know none of your supports will be broken, how can one claim an advantage is not to be had? This is not metagaming but can certainly be considered a moral issue. Yes you know something you maybe should not, but then again, if this were face to face, you would know if a player had to step out for an emergency. How is this different? You also know from your discussions with others that a player may have stopped communicating with others, you know if he has been active, maybe he sent an in-game message to the wrong person, how is any of this used to your advantage wrong in any way?
Let me share a funny (and very true!) story...
Back in 10th grade math, we had a surprise quiz and I was LOST, I sat there just staring at the page and my eyes just wandered to anywhere but the quiz in front of me (no they did not wander to other peoples quizes!) suddenly I notice the blackboard has scrawled on it numbers 1 through 20 with what appears to be answers. Damn, my quiz has 20 questions as well, could it be these match??? I can't tell for sure but the very few things I think I know seem to match up...what the hell!?
I copy them 100% and sit back waiting for the others to finish, the teacher notices I am way ahead of all others (and he knows I'm not the sharpest tool in the shed).
The next day we get our results back, I got a perfect 100%.
The teacher asks the class "did anyone but Mr Reinecker notice the answers were on the blackboard?" One girl raises her hand and says she saw it but didn't take advantage of it because that would be "cheating". He laughs and says this was a life lesson and he says little in life is free but when it is, TAKE ADVANTAGE OF IT!
Same here my friend!
This is available to all and is not cheating so use it to your advantage!