Warriors will probably be a popular class in World of Warcraft Classic, just as they were in vanilla World of Warcraft 15 years ago. They can be tanks or melee damage dealers.
Melee DPS Warriors have some of the highest damage potential in the game. After their very difficult leveling phase, their ability to debuff enemy armor and scale beautifully off of gear make them a must have in most raid groups. But as Warriors are very popular, players will like have trouble competing for gear. Keep in mind that raid leaders may ask their DPS Warriors to tank or off-tank.
Tank Warriors are the best tanks in World of Warcraft Classic. They have powerful mitigation tools and can generate threat very easily, holding a boss’ attention for a long time. They can stand their ground against bosses and shrug off big hits that would likely kill other tanks. They run into the same gearing problems as other Warriors, but most groups favor gearing their tanks over their damage dealers.
If you want to tank or deal melee damage in World of Warcraft Classic, this is the class you’re looking for.