Hype train has been beaten like a dead horse, so I won't go into your first bullet point. The second and third bullet points are critical though, as you are missing the most important part of the issue: communication and expectations.

Expectations are everything in business. If you sell shit on a stick and tell your customers that it is shit on a stick, you are a businessman. If you sell shit on a stick and tell your customers it is chocolate, you are a fraud. Expectations are also the easiest thing to manage as a business because YOU ARE IN CONTROL OF THEM. You get to decide what you tell your customers your product is, what it will do, how much it will cost, how it will be supported over time, etc. The biggest mistake a business can make is to over-promise and under-deliver. With all that established, let's look at the expectations that Overkill have set with their community and what impact that has had on how the community perceives the product:

With regards to the infamy update, Overkill set expectations in several ways that infamy would be more than cosmetic. When it came time to deliver on those expectations, the result was about 55% cosmetic-only and 45% filler. That is a failure to deliver on expectations. If Almir had said during the AMA that future infamy updates would be cosmetic only for balance purposes, this update wouldn't have been a surprise because the expectation matched the reality. "Overkill will always have the chance to go back and add more content to the Infamy system when they aren't so busy." We have no way of knowing if this will happen because they haven't communicated that to us. If they had said anything along the lines of "work in progress," "future updates," "please give us your feedback," etc, that would be both communication AND setting expectations. I think if that kind of verbiage had been included in the patch notes for infamy 2.0 then the community wouldn't have reacted so badly because we would KNOW that it was a work in progress instead of having to INFER that based off of zero information or evidence.

With regards to the early release of the new content, just think about what I discussed above and how communication and expectations applies to this situation. Here we have a DLC that is EXPECTED to be released on March 12th. Most Steam users know that pre-orders can be refunded to their Steam Wallet, but that once the content launches you cannot get a refund. Therefore by pre-ordering content you are buying the EXPECTATION that you will get the content on a certain date, and that if you change your mind before that date you can get a refund. So releasing the content early doesn't look like Overkill doing the community a favor, even if they had said otherwise (they didn't. More on that in a minute). It looks like Overkill trying to re-neg on expectations they set earlier in the Hype Train event by accelerating the launch of the content. So there's expectations, now on to communication. The announcement about the early release of Hype Train DLC stated that they were releasing the content early so that "we could enjoy it over the weekend." This doesn't make any kind of sense, because the content would have been released right before NEXT weekend anyways, so why this weekend and not next weekend? The distrust isn't due to any more or less than a lack of communication.

tl;dr failure to meet expectations + lack of communication = upset community