This is the Doppler effect, not time dilation. They are related but not the same. Time dilation is what you get when you take this direct observation and correct for the travel time of the light signals in order to calculate the rate at which they were emitted by the source. That rate will still be slower for an approaching source; the "slower" is time dilation. No, but it does predict exactly what you describe for the Doppler effect from an approaching source. You will need to give specific references for this very strong claim.