(This schema has seen several updates in 2016 and 2017 since it was first entered into the whitelist.)
As per the talk page documentation: Auto-purge just eventCapsule PII after 90 days, keep the rest indefinitely. This means that an update is needed for the following fields:
event_namespaceIdSource
event_pageIdSource (this is basically redundant to the already whitelisted event_pageTitleSource, but makes some queries easier)
event_namespaceIdHover
event_isAnon
event_totalInteractionTime
event_hovercardsSuppressedByGadget
event_perceivedWait
event_editCountBucket
event_previewCountBucket
event_linkInteractionToken (unique to this schema)
event_pageToken (unique to this schema)
event_previewType
event_version
Also, "event_sessionId" in the current whitelist looks like a typo (AFAICS there was never a field with that name in this schema) and should read "event_sessionToken" instead