Microsoft today blogged that they are working on improving passkeys. Specifically, they will be supporting syncable passkeys stored in Bitwarden (and competitors) via a formal API.
Looking forward to this as Passkeys both seem to have a bright future, but are not yet ready for prime-time.
Well, they themselves (the passkeys) may already be - but the services/accounts, OS’s, password managers etc. are not all there yet. 
All I ask is that they allow you to specify a default selection on the Windows Security passkey prompt, so that I don’t have to click “Security Key” every time (or even better, allow you to completely disable/eliminate the option “iPhone, iPad, or Android device”.
This article says that Microsoft is working with 1P & Bitwarden, not sure if it’s by way of sitting on the FIDO2 board or not. Maybe things will turn out great.