Bungie announced that they will test a new type of matchmaking in Destiny 2 and the first phase is starting with Iron Banana, which is currently in progress.
Iron Banner has had horrible matchmaking for a long while now and the snowball mechanic where one team can lock all three zones in doesn't really help the experience feel better. The matches often end up being mercied, resulting in landslide victories that are not fun for the winning team and utterly dreadful for the losing team.
This experience resulted in endless negative feedback about the game mode and Bungie are now looking to compensate for the removal of skill-based matchmaking.
Destiny 2's matchmaking currently attempts to put an even skill rating on both sides, which is why you can often see the top player in a team wrapping up a match with 8.0 efficiency while half of their team members are stuck with something like 0.47 efficiency. This leads to frustrations due to matches being virtually impossible to carry.
The new matchmaking system will attempt the Snake Draft method. When 12 players are selected for an Iron Banner match, the game will place the best player on one team, second and third best on the other, fourth and fifth on the first team and so on.
Overall, this should prevent situations where the best player in the match is placed in a team that they have to carry almost entirely on their own but there are possibilities snake draft won't do the trick in the long run since skill discrepancies between two ranks can be deceptive.
We have five full days of Iron Banana to test out the new matchmaking since it has been deployed about the same time the TWAB that announced it was published.