Today we were reviewing the EL sanitization white-list (for other reasons) and we saw that the schema MobileWikiAppShareAFact had some fields renamed a couple months ago. However, the corresponding white-list was not updated with the new field names. So, after 90 days of the renames, those fields will be purged (maybe some have been already).
Everytime there's a rename in an EL schema, the whitelist should be updated accordingly, otherwise data loss might happen. See: https://wikitech.wikimedia.org/wiki/Analytics/Systems/EventLogging/Data_retention_and_auto-purging#What_happens_when_I_rename_fields_in_a_schema?
Please, can you make sure that all your schemas that suffered field renames are updated in the EL sanitization whitelist?
I'm subscribing other data analysts to this task so that they can check as well, in case they have schemas in such situation.
I also added Reading-analysis and Product-Analytics (sorry if those tags are not accurate).