The four Yugas (Satya, Treta, Dwapara, and Kali) together make up one Mahayuga. 1000 Mahayugas make up one Kalpa, which is one day in the life of Brahma. After the Kalpa is over Brahma goes to sleep, and there's a Pralaya which destroys the three worlds, at the end of which Brahma wakes up and creates the world anew. But as I discuss in this answer, in addition to being divided into 1000 Mahayugas, a Kalpa is also divided into 14 periods known as Manvantaras, in which a figure known as a Manu rules over humanity. Since there are 14 Manus who rule in a given Kalpa, each Manu rules for about 71 Mahayugas.
Now unless Hinduism Stackexchange manages to survive past the Kali Yuga (!), we are all currently living in the 28th Kali Yuga of the Vaivasvata Manvantara. There are plenty of scriptures that talk about past, present, and future Manvantaras. And there are scriptures that talk about the first 28 Mahayugas of the Vaivasvata Manvantara. For instance, as I discuss in this answer the Vishnu Purana lists the Vedavyasas or compilers of the Vedas in the first 28 Dwapara Yugas of the Vaivasvata Manvantara. And the Shiva Purana discusses the various Yogeshwara incarnations Shiva has taken in the first 28 Mahayugas of the Vaivasvata Manvantaras, including Lakulisha whom I discuss here. And there are various references in the Puranas to incarnations of Vishnu in the first 28 Mahayugas, as I discuss here.
But my question is, what do we know about the future Mahayugas of the present Vaivasvata Manvantara?
I only know about two things that will happen in the 29th Mahayuga (i.e. the next Mahayuga):
In the 29th Satya Yuga, Shantanu's brother Devāpi and Rama's descendant Maru will re-establish the lunar and solar dynasties, as described in this chapter of the Srimad Bhagavatam:
After the one thousand celestial years of Kali-yuga, the Satya-yuga will manifest again. At that time the minds of all men will become self-effulgent.... Devāpi, the brother of Mahārāja Śāntanu, and Maru, the descendant of Ikṣvāku, both possess great mystic strength and are living even now in the village of Kalāpa. At the end of the Age of Kali, these two kings, having received instruction directly from the Supreme Personality of Godhead, Vāsudeva, will return to human society and reestablish the eternal religion of man, characterized by the divisions of varṇa and āśrama, just as it was before.
As I discuss in my answer here, in the 29th Dwapara Yuga, Drona's son Ashwatthama will become the next Vedavyasa or compiler of the Vedas. This is described by Vyasa's father Parashara in this chapter of the Vishnu Purana:
In the next Dwápara, Drauńi (the son of Drońa) will be the Vyása, when my son, the Muni Krishńa Dwaipáyana, who is the actual Vyása, shall cease to be (in that character).
But what else do we know about the 29th Mahayuga?
And are there any scriptures which mention events in later Mahayugas of the Vaivasvata Manvantara?
If not, how is it that we have information in Hindu scripture about events in all future Manvantaras of the present Kalpas, but absolutely no information about the 30th and subsequent Mahayugas of the present Manvantara?