I was just doing a co-op Crucible run, and I had the echo Second Chance to revive after dying with 50% health. I accidentally jumped off a ledge because my character didn’t grab onto the ledge, therefore I plummeted to my death. I was expecting to respawn in the run on a proper ledge with 50% of my health, but low and behold I’m back outside of the run with no way back in because we were on the last level before the boss.
I don’t know if it’s intended to only work if you were slain by an enemy, but if I have an echo that REVIVES AFTER DEATH, I expect to stay in the run, not get kicked out of it.