It has been 10 years since Ajin: Demi-Human season 1 and 2 came out and currently there's no officail announcement for season 3.
which is a shame, because unlike other anime that didn't get another season, you can't just go read the manga, because Ajin season 2 didn't follow the manga's storyline instead it introduced an anime-exclusive storyline and even ended with a cliffhanger.
what a shame.