One of several exciting cosmetics coming in Dragonflight Patch 10.2 is the Tabard of the Tyr's Guard, a white and gold colored version of the incredibly popular Tabard of the Lightbringer from Wrath of the Lich King!
Normally only obtainable by Warriors, Paladins, and Death Knights through completion of the extensive Shadowmourne questline in Icecrown Citadel, the original tabard is one of several bind on use rewards received from the Unsealed Chest follow up quest, alongside Muradin's Favor, Jaina's Locket, Sylvanas' Music Box, and the Reins of the Crimson Deathcharger. At this point, many of these rewards from the nearly 15-year old raid have been obtained by alts or bought and sold on the auction house, but they remain semi-exclusive and highly sought after by nearly all players.
While it's still unclear exactly how the new Tabard of the Tyr's Guard will be obtained, it seems very likely that it will be rewarded at some point in the quest to restore the Keeper Tyr, which reintroduced the human paladin Travard as leader of the Tyr's Guard from Legion.