To be fair, on point 2 it's not really a Valve issue as much as it is a problem with platforms/ecosystems as a whole. If Apple and Google can't even handshake to make messages on their OSes more compatible, then what about their competing app stores? Where they aren't incentivized to be cross-compatible with something like in-app purchases (I know that in some cases purchases carry over to other platforms, but usually it's because of a 3rd party account that keeps track of the premium currency or whatever for that game specifically or a network of games. It's not something done at a platform level). Same would apply to Steam and Epic.

And specifically with Steam and Epic cross-compatibility with DLCs, barring other storefronts for the moment like GOG, etc., I don't have trust in Epic doing so in good faith. If I'm not mistaken, Tim Sweeney made a huge stink on Twitter a long time ago about not having access to Steamworks. If anything, I feel like Epic would want this to happen just so they can piggyback on Steam's work with little effort on their part (relatively speaking) to create an actually feature rich storefront.

Unless something unprecedented happens like the EU making Steamworks an open-standard somehow or some other system be in place, then I doubt point 2 would ever happen or be a substantial argument for the suit.