Hazrat Ayesha (ra) said:
“Call him the Khatim al-Nabiyyin; but do not say that there shall not come a Prophet after him.”
(Al-Suyuti Durr-i-Manthur, Vol. V, p.204)
The same statement of ‘A’isha has been quoted in the Ta’wil al-ahadith of Ibn Qutaiba. In the Durr-i-Manthur a similar statement of Mughira ibn Shu’ba has been quoted through a reference to the Musannaf of Ibn Abi Shaiba:
(It is related) from al-Sha’bi who said that a man sitting near Mughira ibn Shu’ba proclaimed:
Blessings be upon Muhammad the Last of the Prophets, and there shall not come after him any Prophet! Mughira told him: When you say Khatim al-Nabiyyin, you need not further say, there shall not come a Prophet after him. For we have been told a hadith (from the Prophet) that ‘Isa is also to be (again) commissioned: and he was sent before him and (will be sent) after him.
(Durr-i-Manthur, Vol.V, p.264)
Ibn Abi Hatim on the authority of Abu Hurariah that the Prophet once said:
“I am the first of the Prophets in creation, and the last of them in being commissioned."
(Ibn Kathir, Fath al-bayan)
In a long hadith concerning al-Isra’ (Night-Journey of the Prophet), (it is related) on the authority of Abu Hurairah directly from (the Prophet):
“O Gabriel, who is with you?” He said (to the Angels in reply): “It is Muhammad the Messenger of Allah the Last of the Prophets… (till he said)... Then Allah the Blessed said unto him: I have taken you for my beloved. It is also recorded in the Torah that Muhammad sallallahu alayhi wasallam is the beloved of the Most Beneficent. And We have sent you to all mankind. I have made your Ummah the earliest and the last of all the nations. I have also made your Ummah such as no khutbah (sermon, or address) shall be valid unless people testify that you are My servant and My Messenger. I have made you the first of the Prophets in creation, and the last of them in respect of Commissioned. I also gave you the seven repeated (verses - i.e., the Surat al-Fatiha) and I did not give it to any other Prophet before you: and I have given you the last verses of the Surat al-Baqara from that treasure which is (hidden) under the Throne and which I did not give to any other Prophet. I have also made you a Fatih (an opener) and a Khatim (one who ends a thing).”
(Narrated by al-Bazzar - see Majma’ al-zawa’id, pp.27- 29). This hadith is also narrated in the Khasa’is al-kubra, p.171, on the authority of Ibn Jarir, Ibn Abi Hatim, Ibn Mirdawaihi, Abu Ya’la and al- Baihaqi)
It is clear that the term Khatim al-Nabiyyin and Akhir al- Nabiyyin mean only that the Holy Prophet is the last of the Prophets -peace be upon them - in respect of his being commissioned (to the people). From this point of view, it is not infeasible or incompatible to any early Prophet to remain (a Prophet) after him or later to be sent to this world.
And Allah knows best.