The ERP Data Dashboard has now been published: https://www.gov.uk/government/publications/events-research-programme-phases-i-ii-and-iii-data-release.
The Data Dashboard shows how many people with positive PCR test results (cases), reported through the NHS Test and Trace system, reported that they had attended an event that was part of the Events Research Programme. No policy recommendations are being made at this time with respect to this data.