Play: Youth age players are playing in a Senior League. (U19 players playing in a U23 League). Are they allowed to wear metal spikes?
Rule: Rule 3-5g talks about Youth/Minor Divisions and does not make a point of saying youth players. If you look at other protective equipment it says youth/ minor catcher etc (Rules 3-6c, d, and e) so in these situation a youth/minor would be obligated to wear the stated equipment even in a senior division. Since U23 is a senior category the youth/minor players playing U23 could wear metal spikes by the Softball Canada Rule book.
Because all other players in the league can wear metal spikes the U19 player is not protected by not allowing them to wear metal spikes so they could wear them.