According to T212367#5613242, Growth no longer has a use for this data, so we should retire it.
From wikitech:Analytics/Systems/EventLogging#Retiring a schema (expand that list if something is missing):
- Remove the instrumentation code
- Mark the schema inactive by editing the SchemaDoc template on its talk page
- Remove its entries from the allowlist
- Request the deletion of any previously allowlisted data
- There was no entry in the allowlist (see https://codesearch.wmcloud.org/search/?q=ChangesListHighlights) so we can skip the related steps