The Imams عليه السلام do have the knowledge of what was and will be, and that nothing is unknown to them عليه السلام

3. Ali ibn Muhammad has narrated from Sahl from Ahmad ibn Muhammad ibn Aabu Nasr from ‘Abd al-Karim from Jama‘a ibn Sa‘d al-Khath‘ami who has said that al-Mufaddal was in the presence of abu ‘Abdallah عليه السلام. Al-Mufaddal asked the Imam عليه السلام the following. “May Allah, take my soul in service for your cause, does Allah command (his) servants to obey a servant and hide the news of the heavens from him?” The Imam عليه السلام said, Allah is by far much honorable, kind and caring towards His servants than to command them to obey a servant (of His) and then hide form him the news of the heavens mornings and evenings.”