Loot boxes are a confirmed feature in Dragon Ball FighterZ, but they appear to be implemented in a non-invasive way compared to other games.
Way back before the game was about to be released, it was confirmed that Capsules that are common in the Dragon Bal series and games would be included in FighterZ. Now that early copies of the game have begun going out, screenshots have been shared via forums like Reset Era with proof that the loot capsules do exist, though it appears that you'll earn plenty just by playing the game.
The Capsules that operate as the game's loot boxes are purchasable with Zeni, the currency found in most Dragon Ball games. These loot boxes seem to contain cosmetics for the avatars that players control in the social hub. Those that played the beta or watched gameplay of it will recall that you can select a Dragon Ball FighterZ character as your avatar for the lobby to control a chibi version of the character while changing colors. Capsules and the loot inside will let you take this customization a bit further with special outfits and other cosmetics included, according to screenshots of the game's Capsule store.
The best part of all the loot boxes is that it seems players don't even have the option to purchase them with real money, at least for now. Zeni will be earned through normal game progression, but another form of currency called Premium Z Coins was also spotted. These coins are accumulated when you get duplicates from the Capsules to act as a second currency. "Premium" is usually a placeholder for "paid" when it comes to these types of currencies, but Michael Fahey from Kotaku says that he's confirmed with Bandai Namco that the capsules would not be purchasable with real money. Screenshots of the Capsule store did show that there's a prompt to take players to the Xbox store on the Xbox One version though, but it's not known what's for sale once you get there since the page isn't live yet.
Dragon Ball FighterZ and it's refreshing take on loot boxes is scheduled to release on Jan. 26 for the Xbox One, PlayStation 4, and PC.