No other show has even addressed it before. The comics since the New 52 haven't even addressed how he became Nightwing so it isn't even limited to other media adaptations. I enjoy the Superman connection because it goes back to an era where Batman, Robin and Superman were all very close. The original World's Finest.
I think the prison origin here is dumb. Although I don't know if it is dumber than when Seeley tried to tie the name to the Court of Owls in his Rebirth run and have that be where the name came from. I'm glad that went nowhere.