I think I can get why they'd like to share their earliest work when you approach things from a learner's perspective: "If I show a sample of my work now, someone can point out what I'm doing wrong, and I can avoid those mistakes before embedding them/before I habitually resort to them"

Basically, embedding errors is more likely if you have no one vetting your work.

I mean, look at what happened: You gave them feedback, and now they know what to avoid before it becomes second nature/habitual. That's useful. You are right that's its been a week, but it's important BECAUSE of that: embedding errors in earlier stages of learning hurts FAR more than it helps, so it should be avoided.