I think he's got that tendency. Wouldn't say he does it everywhere, but I was certainly surprised to see the extent of it on the front nine of Crooked Stick, where he did planting in the mid-1990s to narrow things up. The Golf Club has a tremendous amount, esp. on the front nine. Heck, at the 16th at Firethorn in Lincoln, Neb. he makes you play through a chute of trees so tight the canopies touch at the top. At Oak Tree, all of the par-5s are organized around trees to create shape to the playing corridors. Same thing at Harbour Town and at TPC Sawgrass -- look how he turns the third shots there at the 9th, 11th and 16th holes.
Maybe, as I write this, I realize that no architect relies more heavily on trees, esp. on par-5s, to create vertical corridors and angles of approach. But while that works fine for high-ball hitters and strong players, it does wear on everyday golfers. I also see him doing lots of extra ornamental plantings to full up space -- esp. at Crooked Stick, and that's where he seems to indulge himself to excess.