Thank you for sharing this, MeraBaid. I think it's wonderful that your teen and their friends felt safe enough to experiment with different gender presentations. You're doing a great job as a mom. 💜
I think you're probably right that a lot of teens, and cis people in general (at any age), experience dysphoric feelings. (And I do mean this apart from dysmorphic; quite simply, many people have biological/anatomical aberrations that make them not quite fit their gender.) The difference with me, though, was that I never felt the need to "try out" another gender; I felt female the whole time, even if I didn't feel like my body was living up to that vision or to my chromosomes. If someone feels compelled to test out another gender, that sounds like a different (albeit maybe related) thing, and it's good they have the freedom to do it (so again, kudos to you as a mom!).
I agree that we need to talk more about how bodies are so diverse (heck, even biological sex is not limited to just 2 options), and that it's normal and valid to have parts that don't match the gender you feel yourself to be. This would save a lot of people a lot of angst and grief, as well as freeing them from the worry that they "need" any sort of surgery.
I hope your teen has reached a place of greater self-acceptance now. Thank you for sharing your story!