As my post says: it's unclear to me which tactic was used with which developers, or how those contracts influenced the promises developers made to preorder customers.
We don't know mostly because those contracts are secret.
There have been good deals for developpers, and good deals that developper shouldn't have taken but still took despite their previous engagements to their funders, but Epic literally had no position to strong arm anyone into anything, and they didn't bait anyone - no one signed then realized "oh damn, I didn't think money for exclusivity meant money for exclusivity !".
Epic just said "hey look at this bag of money, I give it to you if you put your game here".
The developers agreed to the deal. If that meant they had to do something shitty (Like not-provide steam keys to backers who paid for that during a crowdfunding campaign), you should be upset with the developers. They made a promise and then they went back on it.
I don't think it's fair to hold Epic's feet to the fire because a developer took the money. If someone offers you a lot of money to break a promise (and you take it), this is a reflection of your character.
Epic didn't make anyone do anything. They made the choice.
If somebody offers you a lot of money to do something immoral, and you chose to accept it that makes YOU immoral. It also should cast a shadow on the person offering you the deal because they too know what they are asking of you is immoral.
I don't think anyone in this deal is acting in the best interest of users. Some of these options may be better than others for indie devs.
In this scenario, much of the uproar that happened was developers breaking promises, and the blame for that being placed on Epic as well. Epic merely offered better deals(in the form of a better revenue split) and cash offers to developers that are notorious for being poorly funded. I don't see how this is a bad thing.
In fact, I'd make the argument that there being more competition in the PC video game marketplace is a good thing that will benefit the consumer.