Wouldn't this be a diabolus ex machina though?
If it's a problem for good things to happen without supporting justification, but instead out of a metagame desire to make a particular end happen, it seems to me that it should also be a problem for bad things to happen as a metagame desire to make something happen rather than because they are supported by justification.
Doubly so when a dungeon, generally notorious for being sealed or inaccessible for long periods of time, does not normally have an environment beneficial to scavengers big enough or dangerous enough to threaten a party.
It is merely following in the footsteps of its parent (3.5e) and sibling (PF1e). The moment I heard that "D&D Next" would use 3e rules but with "4e streamlining," it was already obvious that this would come to pass.