There is no way Kalinga would go against mighty and expansionist Mauryan empire. It would be suicide. I think it had more to do with Ashoka's ambition and he wouldn't mind more funds for maintaining his massive empire and lavishing gifts on his favourites.
It is a Common Occurrence in History . We might think it is suicide based on logic but our kings didn't think the same . They chose pride and independence over logic .
Aurangzeb destroys the Golconda sultanate when they stopped paying taxes .
Muhammad Bin Tughluq destroys the Kakatiyas when they stopped paying taxes . Siege of Warangal (1323) - Wikipedia Abul Hasan Qutb Shah - Wikipedia