I know you don't like DLC, however using mod tools to give access to paid DLC for free to get around that is a direct attack on an element of their business model and I'm amazed that you think they would tolerate that
Except it's not; it's actually free advertising. You can access every single piece of Dota 2 DLC for free as well, but if you want to use them in proper matches you have to buy them. That's a great way to do it, provided you're confident that the proper game is the mode that the majority of people are going to want to play. Given the historical popularity of mods in CoH, that really isn't a concern at all.
I have nothing against DLC; quite to the contrary, I think it's an amazing tool when used correctly. Relic's DLC model, on the other hand, is fucking atrocious, and now they're cracking down on a modding community that barely exists because they have zero fucking clue how to manage an in-game economy. The negative publicity something like this generates costs a whole lot more than any potentially lost sales from mods that provide access to DLC content.