Yes... but I think that scenario is wrong.
I'm not sure who said it will "speed up".
Try spraying WD-40 directly into your carburetor while the engine is running fine... I think you will find that it will tend to make your motor slow down or die
What I have usually stated is that ....if you have a CHANGE... in motor speed... then you have an intake leak.
I think I usually stated it as "if your motor speeds up or slows down" you have a leak.
I think people see..."speeds up" and stop reading.
A change in RPM is the clue.
Actually.... I hope somebody reads this today and walks out and tries it and tells us what happens by spraying it directly into the carb.
I think WD40 will kill the motor.