You are overestimating this, mod support for Vermintide isn’t like modding for Bethesda games. Vermintide is an MMO, and its design philosophy is based around that fundamental concept.
Mods with new maps - There is no level editor and likely won’t be. Robin merely thought the idea was neat but if tools like that would exist someday it’s going to be well past the point that anyone’s going to be interested. More than that, Fatshark would have to make their stance clear on whether or not it conflicts with their DLC packs.
Discussion with Aussiemon and Unshame in the mod discord brought light on another set of important, related tools not likely to be available either. If they are, very far future, and sanctioning is delayed as is.
Mods with new game modes - See the progression issue. Unless you already have literally everything in the game then the average player cannot care about this in any meaningful way. You have to look at the game itself more than the mods here, too, and ask yourself “Is base game fun to play right now? y/n?” then ask the subsequent questions. But really, no progression is a deal breaker. This is not for the average user in the current state.
Mods with new weapons - Won’t happen. You have to take into account the woeful design of Hero Power & Weapon Balance, adding an entirely new weapon to the game with all its modeling, textures, sounds, having it line up with the PlayFab Backend… And hope that Games Workshop doesn’t ban it outright because this game is under the same effect that Total Warhammer is: You can only use existing assets.
Mods with complete reworks - Heroes will not happen. Playing as something else, swapping models to rats, eh, good for someone making a one-off clickbait video on YouTube. But anything serious will most likely be shot down by a legal issue
I don’t know what ideas crossed your mind when this was announced, but if you were hopeful your expectations were going to be outdone, then that is simply not the case. I was in your shoes once, those were the questions I asked months ago - Level editing? Making new stuff? - and then with the same abruptness that EAC was added, the realm split was made known, then the neutering of progression.
Mutator mods and difficulty modes are only going to be for the twitch charlatans. The mythical treasure of level editing has a whole host of issues that need to be expounded on. Adding anything into the game, like new heroes or weapons, will more than likely incur GW’s legal wrath. When you consider mod support from all angles, it makes no sense that all this effort was put in for something 90% of people won’t and/or can’t use for a variety of reasons.
If theirs aren’t crocodile tears about inventories and progression, then they can salvage it. Simply rename the realms to Official/Unofficial, or Official/Open, like in Diablo 2. People who like to earn and progress the intended way have their side, and others who can make their own fun and enjoy all the game has to offer will have theirs without restriction and it won’t cross-pollinate.
But we are in agreement. Nobody will play with god moders. And you know, we solved that issue in V1, too. Lupo made Host Kick and an anti-cheat, and only the host could do things like spawn stuff. The games were protected. I see absolutely no reason why that same protection and self-policing would fail to apply to V2.