After the changes this morning everyone who completed their placements will have to play one more game to be correctly placed.
We've rolled this fix out to multiple regions, and we've since monitored the effects on player MMR and which leagues players were being placed into, and saw that things were looking much closer to their actual ratings.
Unfortunately, for players who have climbed ranks rapidly as a result of incorrect placement and inflated LP gains, this correction to their actual rank feels punishing. We know some players were excited to be climbing higher and faster than they ever have but it’s pretty likely that the matchmaking for those players was a bit of a clown fiesta in the first place.
Ultimately to be as competitive as possible, we wanted to make sure they (and their opponents) had a fair climb up the ladder and this means resetting everyone to their correct rank.