There is no contradiction between these two matters. The People of Fatrah who pass the test on the Day of Resurrection become believers who submit themselves to Allah. They therefore enter Paradise as Muslims. In this way, the hadith, "No soul will enter Paradise except a Muslim soul," remains general in meaning and fully valid.
The People of Fatrah are those to whom the message of the Prophet ﷺ did not reach in a manner that established proof against them. As a result, they neither believed in the message nor rejected it because it never reached them.
For this reason, their ruling differs from that of those who received the message and then turned away from it or denied it.
The answer is: No.
The Prophet ﷺ said:
"No soul will enter Paradise except a Muslim soul."
This is a general and established principle with no exceptions.
As for the People of Fatrah who will be tested on the Day of Resurrection, whoever obeys Allah's command during that test becomes a believer who submits to Allah. He then enters Paradise after fulfilling the qualities of Islam and faith.
Therefore, such a person does not enter Paradise while remaining upon disbelief or polytheism. Rather, he enters it after passing the test and obeying Allah.
Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him) explained that those to whom the message did not reach in this worldly life will be tested on the Day of Resurrection, and their final judgment will then depend on their response.
Whoever obeys Allah's command will be among the people of Paradise, and whoever disobeys will be among the people of Hell.
He said:
"Whoever obeys at that time will enter Paradise, and whoever disobeys will enter Hell."
This shows that entering Paradise is connected to faith and obedience after the proof has been established.
The scholars have established that the comprehensive principle in this matter is:
Therefore, the People of Fatrah who enter Paradise do not enter it while remaining disbelievers or polytheists. Rather, they enter it after their faith and obedience to Allah become manifest through the test by which the proof is established against them.
And Allah knows best.