Hard to know for sure what is Bungie's exact standard. But I would say that if you play seven matches where you get at least one kill and actually try every round without suiciding then your probably safe.
Eh, I'm sure there will still be people that get screwed over, even if they do more than 7 actual matches.
I never got my free rising light emblem for completing an activity from the director even though I was playing several hours per day completing weeklies, dailies and other stuff during that time. I don't really care about emblems, so it didn't matter to me. A 320 ghost is a different story though.