A quick update: support for passkeys in Discourse is coming soon. I’ve been working on this over the past few weeks and we have a couple of draft PRs ready. See #23586, #23587 and #23591.
I think in about 3-4 weeks, we should be able to merge this (behind a default-off site setting). And if we grant a few more weeks for testing and bug fixing, I suspect we’ll be able to have this production-ready state in about two months. Stay tuned!