Isayama just love to tease like this 'huh.
The only part I'm happy about only reveal that peace is not guaranteed.
So all stuffs Armin working hard about only delayed the inevitable. Logically no way generations that live through such event will easily forgive it. So its a good take.
How the kid found the tree is, my guess, Isayama way of saying "cycle of revenge" is waiting. As if telling whoever tap into Titan powers, especially Paradis lineage, will get full blessing from Eren within Path to initiate chaos once again. No surprise if Eren grave got that kind of secret assuming that spine follow its latest host.
Whether Isayama wanted to pull a Boruto is up to him, although I imagine when Eren connected to the new host he will be irritated learning whoever that man Mikasa chose. LOL.
