In Jain philosophy, Jain Dharma does not come to an end.

What changes is the time-cycle of the world, called Avasarpiṇī and Utsarpiṇī. In one half-cycle, spiritual decline happens; in the other, spiritual rise happens. So:

• Tirthankaras appear again and again
• The Jain path remains eternal
• What may disappear for a time is the availability of proper practice or living Tirthankaras, not Jain Dharma itself

So the correct understanding is:

Jainism is eternal. It does not end with any one era. Only the conditions for practice change according to the time-cycle.

If you want, I can also explain this in the language of Avasarpiṇī, Utsarpiṇī, and the 24 Tirthankaras.