This looks like continuation of cycle.humanity perpetual need to fight and for war. this generation lived and rebuild. Next generation had a devastating war which either destroyed only Paradis island or entire civilization. Hundreds of years passed (that tree is obviously hundreds of years old similar to 500-1000yr old Redwoods in CA.) Young boy finds a hollow of a tree with parasitic titan symbiote (like Ymir did) Titan cycle starts again.
This looks like continuation of cycle.humanity perpetual need to fight and for war. this generation lived and rebuild. Next generation had a devastating war which either destroyed only Paradis island or entire civilization. Hundreds of years passed (that tree is obviously hundreds of years old similar to 500-1000yr old Redwoods in CA.) Young boy finds a hollow of a tree with parasitic titan symbiote (like Ymir did) Titan cycle starts again.