When the emote came out the notice we got with it was 'buy this emote now and get a discount for the lore book'
Nowhere did it say it was exclusive to silver and even bungie said when they announced the eververse changes 'everything will be available for both bright dust and silver on a weekly basis'
As for the arc emotes, they are silver exclusive to my knowledge but that might change...who knows.
It also said something along the lines of "purchase now for this limited offer", which was worded in such a way that myself and the many other rightly miffed people who bought it interpreted as meaning the entire emote as a whole, not the discount on something else to shell money out on. It's shady and misleading whichever way you slice this.