Whether something comes up, a player doesn't like the random strike selected, forgot to drop before the loading screen, or who knows what else - people drop out of strikes regularly. That said, my expectation is that the matchmaking system will replace them and bring our fireteam back up to 3 members as fast as possible. Currently, the system is not doing this. I ran 10-20 strikes this past weekend with a fireteam friend. More than half of those strikes, our third, matchmade member would drop at the start of the strike for whatever the reason. After that we would finish the whole strike and not get a replacement until the next strike. During which the new member likely dropped when it wasn't the strike he/she desired to run. I ran some alone as well and upon struggling with a boss for an attempt or two, members bailed and I was left staring at the boss alone for 10 minutes before I gave up on any cavalry showing up and had to sacrifice my time invested as well as my strike loot bonus. This is all the more of an issue due to that strike streak. People leave left and right and being left to 2 man or solo an instance rather than give up the loot buff and re-que is not an ideal workaround. In all the strikes that I was missing a member so far in the last week, I've had 1 strike find a replacement and it took 20 minutes (enough time for the two of us to clear to the boss) before we got said replacement. I feel like the fact that a replacement was found 1 time after a 20 minute wait suggests the system wants to replace missing members - so I feel like the fact that it regularly doesn't, and even when it does takes forever, is something that should be looked at!