It affects ALL Florida permits in Washington state. Washington state could have just refused to home any one under 21. with out rejecting ALL permits.
How many are even discharged honorably prior to 21 ?
At what age are they REQUIRED to register for the draft ??
You answered your own question. If WA rejects all FL CCW permits, then age is not an issue.
Those FL residents who wish to carry in WA can simply apply for a WA state permit. If WA permits are recognized in FL, there's your solution.
During the Vietnam era, many US citizens registered for the draft at 18. Is anyone required to registered for the draft these days?
Most contemporary Americans are honorably discharged from HIGH SCHOOL at age 18. US military combat vets tend to be a bit older at their discharge. Are 18 year old Florida permit holders allowed to carry concealed on US military bases?
What was your point?