It was in the 80's I think but they began stressing the urgency of baptism for anyone who was "at an age of understanding"
I heard several assembly talks that said kids under ten could be baptized if they qualified.
This sticks in my mind because my kids were 12 or so and not qualified in my view. My ex wife pushed my daughter into baptism at 12, She is now 32, not a Witness and we both laugh about it.