Is it true that a day will come upon Hellfire when there will be no monotheist within it?

There will come a day upon Hell when no monotheist remains in it, because whoever dies upon Islam, even if they were disobedient and Allah did not will to forgive them, they will not abide eternally in Hell. Rather, they will inevitably exit it one day, for eternal abode in Hell is for disbelievers and hypocrites.