Get past meeting participants doesn't detect display name change

We create meetings and register attendees programmatically with the /users/{userId}/meetings endpoints. We set the display name to first name and initial of last name to protect privacy. However, we let people change these names in-meeting if they want.

Our problem is that when people change their name, it does not show up in the
/past_meetings/{meetingUUID}/participants endpoint we use to query the participants inside the Meeting Ended webhook. It supplies the original display name in the registration.

We would like to provide to the moderator of the meeting (often not the host) a report with the names the moderator saw in the meeting.

How do we get those names?