He said "Draft" is gone, you changed it to "Selective Service" which is simply a prerequisite of a Draft. Convenient distinction. There has been no draft since 1973, at the end of the Vietnam war. Suffice it to say, that we have had two full generations of draftable people never see a draft. It is effectively gone.
We don't need a Constitutional Amendment to stop the draft, we already have stopped the draft. A constitutional amendment would only make it harder to reinstate (via another Amendment). And since we are talking about likelihoods and possibilities, and haven't ever reached the point of 0% you are just trying to make an impossible point out of ignorance.
Interestingly, its Richard Nixon that campaigned on ending the draft and the Selective Service, and Carter that re-instituted the Selective Service in 1980. I know, I was alive back then, and someone under the age of 20 probably has no clue about. Liberals have indoctrinated young people so much they thing Democrats are champions of Civil Rights (while they opposed civil rights movement in the 60s) and opposition to the draft.
With age, comes wisdom that youth and exuberance is in need of. So, no, children cannot teach adults anything useful in general. A child may be wise, but adults tend to be wiser than children.