Fat 'drawing internal moisture like a wick'? I disagree.
I'm baffled by your references to 'traditional' Texas brisket, nor do I understand what you think is being pawned off as modern, nor what you mean by the 'subtle flavor', nor, really, what you mean by 'Texas style BBQ'.
There is little in the way of commonality between Q'd briskets in Texas except that they are a) briskets, b) smoked with oak or mesquite depending on where you are in the state, c) fairly smoky, and d) fairly bland. They are not subtly smoked but spicing is little-to-none almost across the board.
Sauces vary in Texas (I've yet to discover commonality there; I'd argue that there is no such thing as a 'Texas-style' to sauce--and that's one of the things I like about eating there: trying different sauces and discovering the occasional really good one as the meat in Texas, to me, often begs for sauce).
Some of the oldest and most famous Q joints in Texas cook at high heat either for the whole cook or part of it (a few cook direct for part to much of the cook, others indirect and high; some wrap, others don't). Others low/slow. There are some differences in the finished product depending on which approach is used and, thus, other than the commonalities noted, differences among the brisket of Texas Q establishments.
Which 'traditional' Texas brisket do you have in mind?