It seems to me that the article is about military recruits, and "will be the last of their kind" refers to the conditions that apply to these recruits mentioned somewhere before in the article. Without seeing more context it's impossible for me to give you more details.
Here is another example to help clarify:
Frank loves his old typewriter. He says "I'll never buy a computer, because they are ugly and I'm too old to learn how to use one". There are very few people like Frank nowadays. Almost everyone in the world types on a computer. Frank is the last of his kind.
I hope that helps.
author of The Secret Lives of English Verbs
Student or Learner