My eight year old grandson gave me a running commentary of about 2 hours on a computer game called Mindcraft. What I noticed was the vocabulary. His older brother has a huge vocabulary but this one seems a bit less interested in reading. So when I found him using words like craft table and obsidian fluently, I wondered if he would transfer these words out into communication beyond the game.
Two instances of this came up. My wife used the word “lair” and I asked him if he knew what it meant and he did. Then in the explanation of the game, he used the words “pork chops” and I recalled that the other day when we were making up a grocery list, he had suggested pork chops. Of course, we use the term pork chops around the house, but he hadn’t shown any particular interest in picking up words like that, so I took that as possible evidence that he homed in on the words in the game and then transferred them out into conversation.
The upshot is that kids may very well acquire vocabulary from these games.