Yes it is. Or so it worked for me. I used to throw the racquet forward, in the direction I want to serve. It makes sense, right? But the results were:
-Lots of power;
-****-poor net clearance;
-Lower angles that made the ball being long most of the time;
-Shoulder pain/cramping (but that may just be me).
And since I'm not tall, I couldn't sustain such a motion.
Then I decided to experiment, look at some videos, and throw upward. Much better net clearance, better angles so the ball doesn't go long as much, no pain, higher toss, automatic leg drive (don't even notice it).
So IMO yes it's like throwing your racquet to the ball instead of the direction where you wanna serve.