At the risk of saying something obvious, there's a possible confound: You have to make sure that the cultures assigning high status to suicide don't assign extra-low status to refraining from it (à la "it really would have been the decent thing for him/her to kill him-/herself"), so that those not committing suicide will experience greater status loss in this culture than in others that don't assign high status to suicide.

There's also the problem of comparing cross-culturally the severity of status loss.