Whoever told you that is lying! If you kill all 3 bosses at the end The Whisper is a guaranteed drop.
English
-
It didn't drop for a dude in my fireteam. He had to run it again.
-
He must’ve already beaten it on that character then. I’ve run it for several ppl on my friends list and you’re the first person I’ve heard say it didn’t drop.
-
He claimed that wasn't the case, he hadn't gotten the gun on any of his characters Not sure what he stood to gain by lying either. Maybe it just glitched.