Responses
The kid is probably not mikasa's child because a significant time has passed ( you can see skyscrapers when paradis is bombed). We don't know if the titans are back, but eren's tree looks very much like the one ymir fell into and touched the worm thing. It's implied that the power of the titans has returned.
Okay so apparently,
Mikasa and Jean got married and had a child.
Levi died.
Mikasa died. (They all died of old age ig)
The world they live in became quite modern (there are buildings)
But a war started (the buildings were on fire and some sort of jet planes appear to be dropping bombs or something)
Then a kid. Whoever child that is. (Most likely- Mikasa's child)
And a huge-ass tree (that actually has a resemblance with the coordinate)
What's the tree? What's in it?
How can you tell the titans will be back?