This task covers deciding whether to keep the AdvancedSearchRequest data stream. For whatever reason, the schema was missed in T259163: Migrate legacy metawiki schemas to Event Platform. If the data stream should be kept, then it will need to be migrated to the Event Platform.
The data stream was introduced as part of WMDE Technical Wishes' Advanced Search project. According to the project page, the last iteration on the project was circa April, 2019.
Events are still being published to the stream at a rate of approx. 190/min.
Finally, the data are being used in the analytics/wmde/TW/AdvancedSearchExtension-Dashboard project. If the data stream should be kept, then this project will need to be updated.