No — shaving hair doesn’t change its thickness, color or rate of growth. Shaving facial or body hair gives the hair a blunt tip. The tip might feel coarse or “stubbly” for a time as it grows out. During this phase, the hair might be more noticeable and perhaps appear darker or thicker — but it’s not.
Even the Oxford English Dictionary throws its hands up and admits “of the actual origin we have no evidence.” But, the OED continues, “the forms dada and tata, meaning ‘father,’ originating in infantile or childish speech, occur independently in many languages.” In other words, “dad” might come from baby babble and entered adult vocabulary from there as “dad,” but it’s not a sure thing.