Shabaaneah is celebrated by All Shias around the world due to the birth of the awaited saviour Imam As Zaman(A.j.t.f.s). Some say that this night is the night through which destiny is decreed whereas others say that this is a bidah and falsification seen from the eyes of both sects. Is this correct?

15 Shaban is a great and blessed night. It’s second to the night of Qadr. In addition to that, it’s the night of the birth of our 12th Imam.
It’s not bida at all.