Is it intended that excommunication (takfir) only occurs after the message has been delivered, and that the Holy Quran has established the proof against them, and what is the meaning of "Qadariyya coupled with knowledge"?

The Sunnis believe in divine decree (Qadar) with its four levels (Allah's foreknowledge, His writing of it, His will, and His creation of the acts of His servants). This is in contrast to the Qadariyyah deniers who reject His will and creation, or even His knowledge. The establishment of proof (Hujjah) upon people depends on their ability to know and their capacity to act, and it varies according to times, places, and individuals. Also, a distinction must be made between the act and the doer. Not everyone who commits an act of disbelief is to be excommunicated definitively until proof is established against them and their excuse of ignorance, misinterpretation, or coercion is removed.