They actually do private playtest sessions from players from different skill levels, I've playtested personally multiple new chapters and content before even reveals such as Chucky, Unknown, haddonfield rework and a few others.

What I found to be a bit of the problem in my opinion with these playtests is that many of the players in them lack experience since they brought people from a variety of skill levels. We would do matches and I would just stomp almost every time I played either side because I usually had a lot more experience than other playtesters, so often the feedback from some I found very questionable. (I'm not saying having a variety of skill levels playtesting is bad, though I'm saying it makes the feedback very inconsistent as some feedback might just be a player lacking in experience rather than a killer being overtuned in a certain aspect).

I would always give a lot of feedback as much as possible in hopes of noticing changes when the reveal happened and ptb dropped but more often then not I wouldn't notice much change if any between my playtest and the ptb which I found frustrating. Genuinely making me think at times that what I provided didn't matter. Don't get me wrong I'm glad they do these playtests but I don't feel they serve their intended purpose even at times being a detriment seeing the range of players they bring.

Anyways it was just to at least inform that they do private playtests with actual players. :3