No it does not.
As has been answered here to the same question you asked 3/28, here when you asked the same question on 4/8, here on 4/9, and almost the same question here on 5/7.
It seems that all of your questions are based on the incorrect assumption that correct exposure for a scene is additive. That is, you appear to incorrectly assume that proper exposure is calculated by averaging all of the luminance values in the frame. This is not the case! Any given exposure value, which is a combination of ISO, aperture, and shutter speed is only correct for a single luminance value.
Look at it this way: If you have four gray objects in a scene and each one has a different luminance value, only one at a time can be properly exposed to appear to be at 18%. If you expose correctly for the darkest object to appear to be 18% grey, the other three will be varying shades brighter than 18%. If you expose correctly for the brightest object, the other three will be varying shades darker than 18%. What most TTL systems attempt to do is adjust the ISO+Tv+Av correctly for the brightest object (just as your camera would normally try to do without a flash), and then add enough flash to raise the other three as close to 18% as it can without also causing the brightest object to be pushed into being overexposed.
What exactly does TTL flash sets its power to?
How do TTL flash metering systems calculate how much power is needed?
Will the camera compensate exposure anticipating for flash?
Does a flash's TTL automatically adjust as I change its location?