Arabic is not the ancestral language of the Sudan. But Classical Sudanese Arabic has been spoken in the Nile Valley for Millennia. Islam and Arabs have been in Sudan for less than 1500 years as a result many Sudanese do not see Arabs as their great ancestors.
Any simpleton knows that Nile Valley history goes back 7-6000 years--not 1500. In the 1980's many Muslims believed Saudi Arabians were going to support other Muslims around the world; and there was going to be a renaissance of Islam. But this didn’t happen. The Saudis did not share their oil money with other Muslim countries. The Saudis did not want to see a renaissance of Islam, they only wanted to spread Wahhabism, which has evolved into various terrorist groups destroying the peace in Africa , and the world.
As a result, many Sudanese want to be associated with their Kushite heritage i.e., the civilizations of Egypt, Kerma and Meroe. Secondly, Semitic speakers did not enter the Nile Valley with the Arabs. A linguistic analysis of Classical Sudanese Arabic (CSA) illustrates that this language has been spoken in the Nile Valley for 5000 years.
As a result, CSA is related to Akkadian and South Arabic, not standard Arabic and Hebrew. This is why CSA, should be called Classical Sudanese Language (CSL), because it is an ancient language that has been spoken in the Nile Valley for millennia. Furthermore, these Semitic speaking Sudanese contributed to Egyptian, Kerman and Meroitic civilizations.
Standard Arabic and Arabs in the Sudan is less than 1500 years old. CSA is 5000 years old. Given the long history of CSA in Sudan, Sudanese who reject Arabism are not wrong, they are just admitting that the history of Semitic speakers in Sudan is much older than Arabs and the East African slave trade.