I was really looking forward to this rumor being true, but no. Slash has shot down the rumor that Guns n' Roses are going to have a new song in Terminator: Dark Fate.
The guitarist told Eddie Trunk, "There's nothing in the Terminator movie. These rumors, they take off and then they get a life of their own. And you can't reel 'em in. They just sort of get tossed around in the wind." GNR launched the Use Your Illusion albums in 1991 with "You Could Be Mine" on the soundtrack to Terminator 2.
Slash did have good news in general about new music from the band. "I think at the end of the day, everybody wants to have a full album released. I don't think that's really changed all that much."
But there still that other rumor out there. You know, the new album rumor. Hopefully that one is true!