Firstly its clear that Isa(As) has died according to the Quran but this answer will be given according to your beliefs.Secondly a lot of anti Ahmadis have claimed this is in tirmidhi but it is nowhere there.
If you assume that Jesus (as) would physically come from the skies and then passes away you would have to dig the grave of Nabi(Saw) which is haram. So this already proves we cannot bury the latter day messiah in the same burial place since we cannot dig that place up.
Secondly it would mean till Jesus(as) has died you would not be able to tell whether he is that real messiah or not because to find out you would have to see him being buried in that burial spot. Till he’s not buried you cannot give him bayah. You can only give him bayah once he dies and is buried, only if buried in the place of Holy Prophet(saw).
A Hadith of Musnad Ahmad states one who dies without accepting the imam of the age dies a death of ignorance so anyone who dies between the coming of the messiah until he is buried, dies a death of ignorance according to you because he cannot do bayah until Isa(As) died (All what you would have to face if you take this hadith literally)
Basically no one can accept the latter day messiah till he is buried.Now lets see this beautiful vision of Ayesha(ra):
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ عَائِشَةَ، زَوْجَ النَّبِيِّ صلى الله عليه وسلم قَالَتْ رَأَيْتُ ثَلاَثَةَ أَقْمَارٍ سَقَطْنَ فِي حُجْرَتِي فَقَصَصْتُ رُؤْيَاىَ عَلَى أَبِي بَكْرٍ الصِّدِّيقِ قَالَتْ فَلَمَّا تُوُفِّيَ رَسُولُ اللَّهِ صلى الله عليه وسلم وَدُفِنَ فِي بَيْتِهَا قَالَ لَهَا أَبُو بَكْرٍ هَذَا أَحَدُ أَقْمَارِكِ وَهُوَ خَيْرُهَا .
Yahya related to me from Malik from Yahya ibn Said that A’isha, the wife of the Prophet, may Allah bless him and grant him peace, said, “I saw three moons fall into my room, and I related my vision to Abu Bakr as-Siddiq. Then, when the Messenger of Allah died, may Allah bless him and grant him peace, and was buried in my house, Abu Bakr said to me, ‘This is one of your moons, and he is the best of them.’ ” (Muwatta Malik, : Book 16, Hadith 30)
Nabi(saw) Abu Bakr(ra) and Umar(ra) were buried in the pavilion of Aisha(ra) as per her vision.
Only three people are mentioned no fourth. If the latter day messiah(as) was to physically be buried there as well, his name would be here
I am the first person whose grave shall be opened [on the day of resurrection]. Then Abu Bakr and then ‘Umar.” (Tirmidhi, Abwabul-Manaqib, Manaqibu ‘Umar)
If Jesus was physically buried with Nabi(saw) his name would have been in this narration also, but clearly it is not mentioned. The true meaning of this hadith is metaphorical and clearly shows us that both the tasks of the latter day Messiah(as) (Who according to ahadith would also be the one who would revive the faith when it ascends to the highest start in the sky, and would be the second coming of Muhammad(Saw) as well) and his master Muhammad(Saw) would be the same and that the messiah would support him in spreading Islam.