Slightly off topic, but have they confirmed they're doing a race/culture book for Elves and Dwarves? After Complete Trog came out I sort of assumed it might happen, but I haven't seen anything official
But yeah, I'm a huge Dwarf enthusiast in tabletop and I will say that I normally like them having their own culture, language, etc, but admittedly that's also a more D&D-esque thing. Realistically, you don't have entire cultures and languages defined by something like ethnicity. The world is just too large and civilisations too spread out for that.
Having said that, it would be nice if Dwarves had some ancient traditions that were discovered from ages past, even in the form of a proto-language that influenced many modern languages. Sort of like 4th World Latin. I do understand that they wanted to do something different with Dwarves as opposed to just making them another completely "different" race, so having them blend into society more easily is interesting.
So here's a random though I had the other day. NOTE: This deals with Earthdawn a bit so is in no way canon.
The worldwide social network and Dwarves just blending into society almost imvisibly was a touch far fetched for me, even for Shadowrun, until I thought about why that might be. Back in Earthdawn days, AKA 4th World, when the various people of Barsaive came out of the caers and formed societies again and then resisted/rebelled rule by the Therans, the main group that formed the foundation of this was the Dwarves in the Kingdom of Throal.
It's established in the lore that people of all raves, at least in that part of the world, looked to Throal for leadership, protection, etc. Even the city of Throal itself (a massive Dwarven metropolis) had such a large population of other races, refugees, etc that there was almost another city outside its walls, as well as a significant foreign quarter. It was essentially one of the earliest Sprawls.
So you have Dwarven society, language, culture, traditions, businesses, and a ton of other things forming the core of Barsaive life for centuries. Now we don't know what happened to the Kingdom in the 5th age, but regardless Dwarves already influenced other societies by over the course of many generations. If the majority of the metaraces became human or humans kind of took over during the low-magic of the 5th World, they'd still have all these subtle little influences and hallmarks they got from the Dwarves they learned from.
So that's why Dwarves naturally fit into Human society better. Because is ways most people will never realise, Human society IS Dwarven society, and Human culture CAME FROM Dwarven culture. Hell most modern slavic languages could probably trace their original syntax to ancient Dwarven.
Dwarves fit into Human society because if it wasn't for Throal, all Human society would be Theran. And Thera...did not end well.