Unlike Gears of War 4, Gears 5 technically doesnt have loot boxes. But dont have a party just yet. It has a convoluted system for unlocking cosmetic rewards that can be used to outfit the characters in Gears 5s many multiplayer modes. Its not intuitive, partially involves microtransactions and will definitely test peoples patience. For those of you playing the game who want to understand how it works, heres a breakdown.
Source: N4G PC How Gears 5s Confusing Microtransactions Work