Apex Legends fans believe Bangalore's Heirloom has been teased on one of her specific skins. Heirlooms are the rarest items in the the game and pertain to a specific Legend. You could potentially find one earlier, but you'll always get one for every 500 Apex Packs you open. At the time of writing, five legends have heirloom sets: Wraith, Bloodhound, Lifeline, Pathfinder, and Octane.
Every week it seems dataminers or a leak are hinting at some Legend receiving an Heirloom, and Bangalore seems to be next one on that list.
According to Redditor breecekong, the Sky Marshal skin has what looks like a K-Bar Knife which is common for military personnel. It's more likely a simple decoration and detail for the cosmetic, as there are a few different knives already used for Heirlooms, and I doubt Respawn would use another knife.
On that note, Respawn Entertainment hasn't confirmed anything about any Heirloom leak or datamine over the past month. But Season 5 should have a new one introduced eventually.