Mentioned previously that i was denied a match from an AA challenge completed right at the end of the year (thus showing low EQM), along with documentation of near-Gold EQM on another airline, to NW Gold.
Unsolicited, I received a further explanation of why they would not accept the match:
Elite status matches are not granted based on the sum of elite
qualifying mileage with various carriers, but rather on the status and
elite qualifying mileage earned with one airline.
Seems fair enough but is a subtle difference from experiences reported earlier here.