I believe some of those arcs could potentially occur in the Dark Continent arc. We already got some hints of a potential new spider member (assuming it is a spider tattoo):
hunter x hunter is an amazing manga and i would love for him to be able to finish it but honestly with the lifestyle he lives and his already existing health issues i don't see him completing the dark continent and some don't even think we'll reach the dark continent
I believe some of those arcs could potentially occur in the Dark Continent arc. We already got some hints of a potential new spider member (assuming it is a spider tattoo):
Well Welfin wanted to find him and here iswhat i really like in HunterxHunter sidecharacters start to get more important Welfinfor example was a side character he had nothing to do with the main character and then he got such an amazing development in Chimera Arc
Its often like Togashi hides possibilities for new Arcs in one Arc The whole Welfin or Zaikahal story might turn into something big unlike Welfin i think Gyro is still evil also Gyros past was mentioned They said at the end he might be in Meteor City
Another Theory if Gyro would be godguy PhantomTroupe will fight Gyros nation because Meteor City is their City
Thats whati think bjt anyway i hope to see Chrollo back and then i wanna see him fight Hisoka with both being serious