So we knew the two trait relics were coming, but we didn't know exactly how they would work.
A reasonable and acceptable assumption would be that the two traits are 'fixed' so matter how many times you loot from said raid boss, you will always get the same two traits. You loot from the older raid bosses, you get the same two traits. It's linked to their item id. That seems fair right?
Except in the 7.2 PTR that's not the case – the relics go along the lines of: "Here's a major trait! E.g. +1 to Essential ability" coupled with "+1 Rank to Random Minor Trait" (actual text in game – also FYI 'minor trait' means any trait that isn't a Golden trait or a Paragon trait – so it will roll into your best DPS traits etc. too).
So not only do I have to roll the relic I want, I have to hope perhaps that it warforges and titan forges AND to top it all off I want that relic to ALSO give me a minor trait that I want.
RNG on top of RNG on top of RNG. Should be the tagline for Legion at this point.