I'm curious, so I had a look through myself.
I am sure it's using West Falls vehicle models that were reskinned. Kinda ironic considering I helped make that mod too. I don't know the usage rules that Slate/Dennis put together for that but I personally think he's getting screwed because he worked on those rigs too.
Have they stolen anything? For the time being, no, because I haven't seen their credits file or if they've borrowed any code that wasn't supposed to be out. I wouldnt know unless I had the files, which I dont, so I won't make any claims on my end.
Where I do disagree is that they're releasing a reskin mod of the same area, same idea, and using Montana assets, some of which weren't allowed for reuse in other mods. I can't keep track of them all but there's quite a bit that I did not allow for repackaging into other projects.
I'll leave it to bama to make a decision on this, because this mod isn't my idea, but his. It's also his map, his map texture, and I will have to hear from him directly if he gave permission for his texture and map work to be altered and redistributed.
I don't have an exclusive monopoly over LA or Montana, but they could have chosen to be more original, or made more content than what I see here. The whole project is low effort and doesn't actually do anything to elevate the game.
What do I plan on doing about this? Nothing until I have proof. The most I can do right now is put together a better project and let the work speak for itself.