I mean yeah, they could come up with some excuse haha.They could probably come up with some scientific reason or create a separate universe. They simply went so far back in time that it looped back and they ended up far in the future. At best they would then not use the typical future setting but paint a world where everything is plant based.
I honestly think Ancient Greece would be their next location.
It's a somewhat popular setting and they have so much mythology to draw from