Active Production, No Series Tag
The 878321211: Packaged in a box, not tape-and-reel or tube, so plan for manual placement or a feeder change if the line expects reeled headers.
Sourcing and Compatibility
Compatibility with existing Molex headers depends on the specific pitch, circuit count, and keying — none of which are documented in the available spec record. Physically verify the mating half before committing the BOM.