The answer is simple. Stardock wouldn't do this. It makes no sense, because the games Stardock have made, or published all have had modding in mind. In a hypothetical situation. If they did allow modding in a beta. They would explain in great detail "Why" they allowed it, and "Why" they stopped allowing it. It more than likely would be for very good reasons. It seems one is looking to bait for malicious intent. Where Stardock has proven to be anything BUT malicious.
IMO nobody should consider making any mods until after the game is released, because who knows what, or how much the game will change between beta, and the actual release. Therefore Relic would be correct in blocking access to modding. They obviously allowed it to show the modding features of CoH2, but now need it closed so that they can work on finishing the final product. TBH Relic was VERY gracious to allow, and support modding in beta before the game was finished. They did not have to do that.
The OP is making much ado about nothing.