No, that is incorrect. The roll center is determined by extending an imaginary line from the upper camber link and the lower control arm (if you draw a line through the hinge pins) until the two intersect. This is called your instant center (IC) and is the imaginary point in which the wheel, camber link and arm rotate about. Then drawing a line from the center of the tires contact patch to the instant center, and doing this for both sides of the car and the point in which the these two lines intersect is your roll center.

When you lower the upper camber link it is essentially like drawing another parallel line under the original location and as a result the IC changes since the lines intersect sooner and thus the line from the tires contact patch is even steeper and therefore actually raises the RC slightly.

One thing to keep in mind is that this only determines the 'static' roll center, but when the chassis rolls through a turn the roll center migrates around and how much it moves is influenced by the suspension geometry.

Heres an image that I just googled that should hopefully help illustrate what I said: