Does noed hurts killers because it maybe inflates the kill rates?

Given that killers get nerfed based on kill rates, you're probably not wrong. If NOED didn't offer a chance to get a kill in the end game, numbers would probably be at least 1 lower in mid mmr brackets.

They can filter out matches with certain perks from their data if needs be.

I don’t think it makes much difference as although they say they use kill rate to balance killers, they selectively choose when the kill rate statistics apply.

For example the last stats had Nurse at the bottom and Blight around the middle (just under Legion lol).

Kill rate is not a good metric to use as it doesn’t count the many factors that affect it; as the killers above are considered the ‘best’ but people playing them at lower ranks make them look worse statistically because they are harder to play. Also it doesn’t take into account wether the kills are suicides on hook, survivors stomping a killer and then refusing to leave at the end ‘giving’ the killer kills, or when a killer only gets 1 hook right at the end but the other 3 throw their lives away trying to get all 4 out.

It really isn’t a good or accurate metric to use for many reasons, as we see with the kills vs escapes MMR issues.

The opinion of streamers means exactly zilch. They are only entertainers and have their own biases. They often miss the big picture.

Some even do their analysis by looking at the outcome of games matching their pro level against the average (good) player and use that as "proof".

I doubt it, usually noed only gets the killer 1 kill, maybe an extra one if they had someone dead when the last gen popped

I don't think it's super common for a killer to get a 4k purely from NOED

Killrates are definitely not the only deciding factor behind what the Devs balance for.

If that were the case, Nurse would have received massive buffs by now and the Deathslinger, who, prior to his nerf, sat on an even 50/50 escape/kill ratio (according to the last stats we got prior to his nerf), would never have been nerfed.

Not to mention that the Devs can tell which Perks have been used, so they can most likely tell when NOED influences an individual Killers killrate.

The killrate is taken into consideration when it comes to nerfs / buffs, but it is definitely not the only thing they look at, nor do I think its the primary thing they balance for.

Chat filters are actually surprisingly complex (if you don't want them to be bypassed in 2 seconds), and as far as I know BHVR aren't actually developing the chat filter, I'm pretty sure they outsourced it.

I suspect it does, at least at low-mid MMR. Low especially, because you can have a genuine baby killer that doesn't know to pressure gens, or who stops to kick every generator mid-chase, or commits to a single chase all game, that will whack someone with a 4% speed boost and Exposed, camp the hook, and get at least one kill out of the deal because nobody can go for the save without dying unless some rare solo queue neurons start firing and someone looks for and finds NOED - which, if it's low MMR survivors matched with the low MMR killer, probably isn't going to happen. I've seen it happen plenty of times where the killer has 0-2 hooks all game and gets kills with NOED - 1k if people leave, 3-4k if people attempt to rescue.

At mid-high MMR, NOED weakens somewhat outside of dedicated endgame builds because survivors know what to do and know where totem spots are. Virtually nobody prevents NOED from appearing, because there really isn't enough time to find all 5 totems without a map unless the killer is awful and boons are more important anyway, but survivors get better at handling it once it activates and it's less likely to get a 4k on its own. SWFs in particular can decimate it (unless they decide to be suicidally altruistic in the name of friendship.)

It mainly hurts new killers by moving them into an MMR bracket where they can only get kills with NOED and sometimes get none. It's a big factor in low MMR and becomes less and less important as MMR goes up. Higher MMR survivors know the totem spawns and will leave an obvious spawn untouched while cleansing (or booning) the out of the way spawns.

That way NOED kicks in, the survivors cleanse the obvious totem, and NOED gets one or two hooks. NOED is an uncoordinated solo team stomper and uncoordinated teams should lose more often than they win. Even at mid MMR you'll see solo queues coordinate in such a fashion that, if you hadn't played solo, you'd think they were a SWF. People complain about NOED since it is overtuned against newbies but it's not against everyone else.

I think Rancor isn't complained about in the same way because you have plenty of advance warning if you're paying attention and know ahead of time that you're going to have to play around it. It also only works on one survivor barring the obsession changing somehow.

In fairness, the killers that use NOED the most are the ones that tend to need it - Trapper and Wraith immediately come to mind. Part of it is because they're both newbie killers and newbies use a lot of NOED, but Trapper needs a fallback if gens go too fast/survivors call out traps, and Wraith doesn't have a lot going for him but the ability to get in the first hit.