[PsYcHe]

Not necessarily, are the D2 not a 4-way ABS system with an independent feed for all 4 wheels, so I'd find it strange that both rears have gone.

I'd pop the calipers off and rewind them to see what happens as I'm struggling to see what could have caused both to go at the same time just at MOT time.

A similar (though reverse) issue is found with the XC90 (like the missus has). As it's a foot operated handbrake with noddy little shoes inside the hub (a daft system, but anyway), if the tester can't generate a decent amount of pressure with their left foot, then it won't pass an MOT.