They are not "Linked" in that they do not share any common brake fluid. There are still two distinct brake fluid circuits here for front and rear.
They are "Semi-Integral" according to BMW. Integral means that the ABS unit has a proportioning valve that allows some brake input from either lever to be applied to both wheels. Semi means that the front brake lever will apply some braking force to the rear wheel, but the rear pedal does not apply any force to the front brakes. This configuration allows for more "sporty" riding, such as smooth trail braking into corners without upsetting the chassis stability.
In contrast, the LT has Full-Integral brakes, meaning the rear pedal also affects the front brakes.
Integral also refers to the fact that the amount of braking force applied to the "other" wheel is proportional, depending on the bike's speed, loaded weight, available traction, etc.
This is a much more sophisticated system than older "Linked" systems that used a simple mechanical valve to apply all brake inputs to all calipers, or that hook the front brake lever to some front and some rear caliper pistons, and the rear brake lever to some rear and some front caliper pistons.
The older Servo-ABS system also added hydraulic pumps that amplified the effort put in at the levers and gave a stronger (and quicker) response at the calipers, especially during full-on panic braking. This system, used on '06 GTs and '02 and up LTs, has four separate brake circuits. There is one for each lever/pedal, and one for each set of calipers. All four of these circuits needed to be bled separately.
Welcome to the wonderful world of German engineering excellence (and expense).
'13 Dark Graphite Metallic K16GTLD, 24K miles and counting...
'09 Magnesium Beige Metallic K13GT, 60K miles miles and counting...
'02 Mauve Metallic K12LTC, 106K miles and sold
BMWLT#145, IBA# 366, MOA# 111996, SCMA# 24032
All lower 48 states plus Alaska on the K13GT in two weeks . . .
Some people see the gas tank as half empty. Some see it as half full. All I care is that I know where the next tankful is coming from...