The routing is quite clever. It adds several hundred yards, allows for a much larger driving range, and a par 3 course on the same land! Tree removal also opened some nice vistas across the property and the city.
It looks like they kept the old 1, 4, 5, 6, 7, 8, 9, 14, and 18 (now 10, 13, 5, 6, 7, 8, 9, 3, and 18, respectively). There are some nice updates on the old holes with more interesting bunker and more strategy as you mention (e.g. nice tie in between 8th and 13th fairways, originally 8 and 4). There are some subtle tweaks: 18 is lengthened as a par 5 that begins close to the old 13 tee, 8 is shortened to a long par 4 by bringing the green forward, and that allows 9 to be a par 5 beginning to the right of the old 8th green.
Then they found a lot of empty space in the old center of the golf course where the old 12, the beginning of 13 fairway, 15, 16, and 17 were. The new 1 begins in the old driving range and ends at the old 11 green. 2 is a par 3 going to the old 13 green, 4 is a new par 3 making use of the turf nursery that used to be right of the old 15. 11 replaces the old 2 with a short par 4 up the hill, moving the tee back to right of the old 3rd green. 12 takes some of the land that the old 3 has and is long downhill Biaritz par 3. The new 14th is a long par 3 that replaces the old 16th -- but actually goes to the green site of the original Watson 16th green which was on a hill behind and to the right of the old 16th. Then 15, 16, and 17 are new long par 4s which traverse across the terrain of the old 16th, 17th, 15th, and 12th green. This leaves space for a huge driving range and par 3 course where the old 10th and 11th holes were.