Currently the volunteer data feed only includes records that were updated in the current year (volunteer_participation_updated_date = current year). Meaning a volunteer activity created in December 2022 for a June 2023 event will not show up in the 2023 volunteer data feed until that event is updated in 2023.
This idea would be that volunteer_participation_date & volunteer_participation_updated_date are both included in the logic that determines the calendar year data that is included.