It's part of proactive bug fixing (Destiny)

by Monochron, Tuesday, April 21, 2015, 20:49 (3345 days ago) @ DiscipleN2k

That said, I'm also having a really hard time understanding what intentional change from the latest patch could have bled over into this specific encounter to make it look so much like a really poor solution for what shouldn't even be considered a problem. This is coming from someone with just slightly more than zero coding experience, but the only thing I can think of that seems like it could be even remotely related is some mention of reduced enemy spawns for the Valus Ta'aurc encounter. Anyone have any other theories?

-Disciple

My best guess would be that they patched a bug that we didn't know existed, and this was an unintended side effect. Could have even been specifically with that door.

Say for instance that after triggering the encounter, if you dismounted a ghost (ahem, sparrow) and phased through that door it would immediately despawn all the enemies (because you "left the area" and need to load a new one) and the game would move on to the next objective. They fixed it so that "leaving the area" through that door early will not allow the encounter to progress. Finally, they didn't realize that the game counted the rock outcropping as "leaving the area". So if you are up there the game won't progress to the next objective and just keep loading the current one.