It feels like a concession made specifically for Shadow of the Erdtree.  I don't think it will end up really affecting outcomes in most years - you could probably count on one hand the number of DLC expansions ever released that even merit a nomination, let alone the win.  Ultimately, I think this just telegraphs that Erdtree is being seriously considered, and they needed to change the rules to make it happen.  Not a great precedent, but also not one that I think will matter in the long run.
