Getting ready to roll out WHfB but unsure of what happens to existing hello standard

We are getting ready to roll out windows hello for business and begin testing within the IT department. Going to be piloting WHfB with okta verify and yubikey Fido.

I’ve done WHfB rollout before but at that company windows hello standard was never used. At current place there are at least some users who have hello standard setup. I don’t have exact numbers.

I haven’t been able to find anything from Ms on what happens when you trigger enrollment for WHfB when the user may have already set up hello standard?

Anyone have any docs they found or first hand experience as to what happens, user experience, etc.

Thanks