I can't see how having Telltale make a Dragon Age game would add anything to the Dragon Age universe. I also can't see it bringing people to the existing games either since BioWare prides themselves on the story aspects of the game more then anything else and that is all Tellale does because the play so drastically different.
1) It won't affect the lore. Usually when Telltale makes a game within a universe it is more a side story. While you may meet central characters within the universe the story is usually something far off. It's not like I'm asking them to make DA 4 with Telltale.
2) It doesn't matter if both pride themselves on story because the story they could tell would be fundamentally different. When Bioware tells a story within their universe it is a story that advances their world. Whereas when they reach out to other companies for example that mini-game in DA Keep, the story they tell is exactly like the kind of story I would love to play without all that extra game-play dynamic.
The part about them not bringing people into other games is your opinion. I didn't even know what Borderlands was and didn't become familiar with Telltales until last year. Now I have 3 Borderlands games, why? After playing Tales from Borderlands I wanted to understand the lore behind the games and the decisions I was making. I know I'm late but I just started watching the Walking Dead...