So I heard this rumor 2 days ago on twitter that someone who worked at DreamWorks told about when will the next seasons of 3below show up he said that season 2 will show up in summer of 2019 and season 3 will show up in winter of 2019 and season 4 which he said is the last season will show up in 2020, sadly his twitter post and account was deleted possibley by Netflix or DreamWorks also he didn't mentioned anything about Wizards the final tales of arcadia TV show.
So one thing i want to say is that I really think this rumor is true and I know that trollhunters had three seasons but remember season 1 it had 26 episodes because originally it was going to have 13 episodes but since the other episodes for season 2 were completed Netflix demanded DreamWorks to release all the episodes as season 1 so because of this the show only had 3 seasons.
I dont know how many episodes we will get in season 2 of 3below but all i know is that this rumor is true hopefully.
but let me know what do you think about this rumor and comment about it if its true or not.