Bungie's idea to make it so that people without the expansion can still do nightfalls on original map packs that they purchased and still do trials on map packs they have purchased is fair. If you are going to Institute this rule then you should also put them on a rotation every other week or so otherwise people cannot plan ahead their raid groups. However changing the prestige achievement to only apply to the raid is not fair because I earned that in a Prestige Nightfall. Also as a paying customer it's unfair to remove a source of 330 light gear for my raiding experience. But all in all you have come up with the most Fair solution you can in the time allowed so I say good job Bungie.