From https://mongodbcr.appspot.com/198870002/:
All of the bulk option structs in generate-opts.py specify allow_extra=False, so none actually accept extra options that we don't know about. That's inconsistent with the non-bulk option structs, which rely on the default allow_extra value of True.
- is related to
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                    CDRIVER-2661 mongoc_bulk_update functions reject arrayFilters option -         
- Closed
 
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                    CDRIVER-2373 IDL for functions that take flexible options -         
- Closed
 
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- related to
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                    CDRIVER-4371 Remove handling of extra options for bulk write update/replace structs -         
- Backlog
 
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