Did MM Change Mid Season?

Games were balanced and then this week, its landslides one way or another, did the programming change that does match making?

https://wiki.guildwars2.com/wiki/PvP_Matchmaking_Algorithm

When you click that link to read algorithm notes, it should just bring you to a page that shows this:

Well, you know, people may randomly start/stop playing PvP at any point. So a rating of 1400 may mean different things at the start and at the end of a season. As an example: Let's say that last season at the middle of it an "alright" player reached rating X. He plays a match from time to time to keep decay away. He takes some break and then next season these people suddenly start to play a LOT of matches suddenly. But the thing is people on rating X are actually not just "alright", but instead "very good". It's a vague way of describing it, but generally it means that as we move forward in time rating X means a completely different skill level. And with a means to easily retain that rating that's what you get. You get multiple people with the same rating, but completely different skill levels.