Could Taric be consider a Juggernaut
I don't think he really fits the bill.
Juggernaut, as far as I understand it, mostly just means tanky DPS. The fighter that exclusively uses defense to survive long enough to do damage, the Barbarian class in your standard fantasy game.
Essentially: Fighter.
Main issue with Taric is he isn't tanky DPS. He isn't a fighter.
He's tanky CC, a straight-up tank.
His main goal isn't to survive long enough to do damage like any self-respecting barbarian or juggernaut. His job is more the paladin roll of initiating a fight, locking down priority targets, peeling and protecting his allies, buffing his team, debuffing his opponents, and making a point to take hits for his allies.
And as far as any potential reworks are concerned: "Tank" really does heavily allude to a Paladin.
Taric is more of a Paladin than any other champion in LoL.
If anything, his rework should move him to a 10/10 on the tank scale and make him everything a Tank primary means. Riot would be doing an injustice to Taric players if they made him a fighter.
Not that AP adventures Taric isn't fun or top-lane isn't the best place to take him ATM, but he really should be more of a Maokai, Leona, or Braum than a Sion, Nasus, or Darius.
Also, there are plenty of Nasus wanna-be champions in LoL.
There aren't a whole lot of proper tanks, so running in the tank direction would allow for a more unique niche and reason to pick Taric.