In Superman: Rebirth #1, Lana Lang and pre-Flashpoint Superman head to the New 52’s burial site to deal with his death in their own ways.
For Lang, it’s to keep a promise and have Kent’s body taken to Smallville, Kansas, to be interred next to his parents. For the original Superman, death is only another beginning. Having been reborn after being killed by Doomsday, Superman believes the same can happen to this timeline’s Superman — provided there’s a Fortress of Solitude with the proper resurrection tech.
Lang, who somehow gained the knowledge of the Fortress’ whereabouts when Superman died, leads the new (or old) Superman there. While they’re devastated to know that Superman cannot be resurrected, they honor him in their own ways.
Superman: Rebirth #1 seems geared as a primer — a way for new fans to jump in and for old fans to get caught up with the whole Rebirth thing going on. While, at best, it’s a moving tribute on the subject of existence if you can dig deep into it, the issue is rather cut and dry with an anti-climactic plot point that’s meant to establish more of the old continuity going forward.