This seems a moot point, Islam has continuously been seen as strange by unbelievers, the saying says it would “revert” to something strange indicating a change in it’s perception, and perhaps indicating a purely Muslim audience that it was addressed to.
I suppose you are referring to these Traditions:
Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “Islam began as a something strange and it will return to being strange, so blessed are the strangers.”
Source: Ṣaḥīḥ Muslim 145
Also:
147- Ghaibat Nomani: It is narrated from Ibne Uqdah from Ali bin Hasan Taimili from Muhammad and Ahmad sons of Hasan from their father from Thalaba from Jomi Kunnasi from Abu Basir from Kamil from Imam Ja’far Sadiq (a.s.) that he said:
“When our Qaim will appear he will call the people to a new faith like the Messenger of Allah (s.a.w.s.) has called and indeed Islam has begun strange and it will return strange as it has begun. Blessed are the strangers!”
148- Ghaibat Nomani: It is narrated from Abdul Wahid from Muhammad bin Ja’far Qarshi from Ibne Abil Khattab from Muhammad bin Sinan from Ibne Muskan from Abu Basir that Imam Ja’far Sadiq (a.s.) said:
“Islam has begun strange and it will return strange as it has begun.
Blessed are the strangers!” Abu Basir said: “Please, explain to me what this means!” He said: “The Qaim will invite to a new mission as the Prophet (s.a.w.s.) has done.”
150- Ghaibat Nomani: It is narrated from Abdul Wahid from Ahmad bin Muhammad bin Rabah from Muhammad bin Abbas Ibne Isa from Ibne Bataini from Shuaib Haddad from Abu Basir that he said:
“I asked Imam Ja’far Sadiq (a.s.) to explain to me the saying of Amirul Momineen (a.s.) “Islam has begun strange and it will return strange as it has begun. Blessed are the strangers!”
He said: “O Abu Muhammad, when the Qaim (a.s.) appears, he will invite to a new mission as the Prophet (s.a.w.s.) did.”
I got up, kissed his head and said to him: “I witness that you are my Imam in this life and in the afterlife. I support your guardians and resist your enemies. I witness that you are the guardian of Allah.”
He said: “May Allah have mercy upon you!”
Its Quranic evidence is in this verse:
"Say: "My Lord hath commanded justice; and that ye set your whole selves (to Him) at every time and place of prayer, and call upon Him, making your devotion sincere as in His sight: such as He created you in the beginning, so shall ye return." Some He hath guided: Others have (by their choice) deserved the loss of their way; in that they took the evil ones, in preference to Allah, for their friends and protectors, and think that they receive guidance" 7:29-30
Meaning, just as in the beginning of Islam some were guided, and some were not, in the same way, your return will be. So, just as in the beginning of Islam, the believers and their religion sounded strange to others, so it will be the same when the Qaim comes when He invites to a new faith and mission.
108- Ghaibat Nomani: It is narrated from Abdul Wahid bin Abdullah from Ahmad bin Muhammad bin Rabah from Ahmad bin Ali Himyari from [Hasan bin Ayyub from Abdul Karim Khathami from Ahmad bin] Hasan bin Aban from Abdullah bin Ataa that he said:
I asked Imam Ja’far Sadiq (a.s.): “When the Qaim (a.s.) rises, what will he do to people?” He said: “He will annul all that has been established before him as the Prophet (s.a.w.s.) has done and he will resume Islam anew.”
Meaning, just as for example when Moses or Jesus had come and established Islam in Their own time, with its own Laws and Rites, and then Muhammad later abrogated the older Islam, and brought a newer Islam in comparison with older Islams that previous Messengers had established, likewise, the Qaim will do the same thing similarly; he will abrogate older Islamic Rites, and instead will establish a new Islam. This would be very strange to the Muslims, in the same way, it was strange for Christians and Jews to accept the Islam of Muhammad as a true Religion! Therefor just as we see in verses 7:29-30 of Quran, at the time of Qaim, some will be guided and some will not, just as it was at the time of Muhammad when He brought the Islam.