Is it obligatory to condemn specific deceased polytheists to Hellfire as part of Tawhid, and is this ruling islamically sound?

One must believe that whoever dies upon a religion other than Islam is a disbeliever, eternally in Hellfire, based on the Almighty's saying: "Indeed, those who disbelieved among the People of the Scripture and the polytheists will be in the Fire of Hell, abiding eternally therein. Those are the worst of creatures." (Al-Bayyinah: 6). As for a specific disbeliever, one cannot definitively assert their entry into Hellfire except with a specific text, as explained by Ibn Uthaymeen. The Permanent Committee has stated that the creed of Ahl al-Sunnah is not to judge a specific individual as being among the people of Hell or Paradise, except for those whom the Messenger of Allah, peace and blessings be upon him, testified for, knowing that whoever dies as a disbeliever is among the people of Hellfire.