You can’t open the same SIVA caches multiple times on a character though.
It seems as though Bungie have made one pretty important change to how raid and loot drops for raids work with the just released Rise of Iron expansion- but it seems as though you still receive SIVA key fragments at each loot checkpoint even you’ve already ran the raid on that character for that week.
While you cannot open the same SIVA caches multiple times on a character, you still can gather more SIVA key fragments, which you can then use to re-roll raid armor or use ten of to make a SIVA cache key- both things that players will doubtless appreciate, and which should make the end game grind in Rise of Iron more palatable.
Destiny: Rise of Iron is the final expansion for Destiny, ahead of the launch of Destiny 2 next year. It is available now on Xbox One and PlayStation 4, becoming the first Destiny product to drop support for the Xbox 360 and PS3.