Something fishy about this new MMR
"We have been running smaller tests of the system on select Xbox One regions for the past few weeks, and the results have been encouraging" and "We are no longer allowing Killers to switch their character while searching for a match, or once in a lobby (excluding Custom Matches). This will allow the new Matchmaking System to track player skill with each killer individually and match them against more appropriately skilled opponents based on their killer selection", two kinda contradictory sentences.
how have you been able to track enough data to feel confident in rolling out this new MMR without locking the switch on XBOX? This either means that you can track data even with killers switching, or that the data you've gained isn't that much good.