It looks like "Hannibal" Season 4 can still happen according to writer Nick Antosca. The series was first announced to be canceled but showrunners are not quite ready to give up the series.
The writer was recently asked about the series and said "I can't speak in detail, but I have heard conversations about what a fourth season would be" If this is true, fan are curious where the show will air, given that NBC has already canceled it and it seems Netflix has declined on saving it. Speculations claim Amazon Prime might be the one to air the show since it is the one that holds the rights to stream its previous three seasons.