They are there as vents. You guys over here in the vaping community seem to be adamant about vent holes. In the Flashlight world (where I come from) I have built hundreds of Li-Ion powered Flashlights with no vent holes and that are fully O-Ring Sealed.
What kind of loads are you running with the flashlights? A lot of vapers are pushing sub Ohm loads which is pretty much a dead short. I have never seen a battery go Chernobyl but there's a few modder's here that have. I guess it's a liability issue.