Okay.
Bethesda will do what Bethesda does and make a decent Bethesda Shallow Sandbox Experience game that will sell 25+ million copies and receive critical acclaim. But they are incapable of understanding what makes the Fallout franchise tick, and their Bethesda Shallow Sandbox Experience design formula is fundamentally at odds with what makes Fallout special.
One example, exploration is key in a Fallout game but not necessarily for the reasons one thinks. One thing Bethesda does well is implement tourist tier exploration where players are essentially divorced from the world and allowed to "explore" and "experience" content at their leisure without risk or reprecussion. In the Elder Scrolls games, this has been lampshaded by the fact that you are some special hero of prophesy, but that doesn't cut it in the Fallout franchise. Worse still, no great effort is made to make the player character play by the same rules as everyone else and this has a big influence on how you can leverage world design and game mechanics for the purposes of environmental storytelling.
The point being, environmental storytelling is one of the primary ways a game can avoid the "tell, not show" pitfall that plagues most games, wherein expository cinematic sequences are the primary means to deliver a story, as opposed to anything that is done through the gameplay (and is able to be interacted with). I have a great (mundane) example that I wrote a blogpost about on the old BSN that features New Vegas and the Van Graff family. How that was a notable example of environmental storytelling, and urging BioWare to look at storytelling like that to escape being unduly tied to their cinematics for writing and storytelling. Some random blogpost by a nobody obviously falls on deaf ears, but it's equally applicable to Bethesda who wish to emulate the BioWare cinematic heavy storytelling style while also not diverging from their original formula.
So, how is that relevant to exploration? Simple. The Bethesda Shallow Sandbox Experience goes out of it's way to treat the player with kid gloves. Eliminating serious risk and repercussions to the player's antics closes off many avenues in which a developer could subtly reinforce narrative themes or show off characters through gameplay, "showing, not telling", whilst also not having to dedicate resources to a cinematic sequence.
Ask yourself this, will a Bethesda game ever feature something along the lines of a Vault 11? Probably not, because they don't want to inconvenience the player, and they lack the ability to craft an environment and set the tone for such a climax to happen in the first place. Hell, lining parts of the map with Deathclaws or featuring Cazadors as an enemy were bad enough, according to many gamers who have been acclimatised to the Bethesda Shallow Sandbox Experience model.
This design mindset also manifests issues in other areas, especially if you want a game with meaningful choices and mutually exclusive content.
"Environmental" storytelling doesn't really work well and it's pretty hard to pull off. I'd appreciate a link to your Van Graff example though.
I found NV on this front to basically reduce to story telling by way of archeology. Take the abandoned vaults. They all tell the story in the same way, and it's ultimately less interactive than cinematics and a lot more about "telling" than showing, because it's always the formula of "here's the aftermath and some journals on why it all went wrong".
Trying to recall the VGs, I'm guessing what you're thinking of is that we come across how the Van Graff family is implied to have a lot of pull in the NCR through background dialogue to each sidequest? I wouldn't say that's really environmental storytelling.