Two reasons I say this.
1). I don't see any reason to get another corner in the portal if we're expecting Jackson to stay. Maybe we'll try to move him around to other positions, like Nickelback. But the guy has always played at corner, and was really good at playing there when he was at Utah. He's a physical player, so moving him to nickel wouldn't hurt him in that aspect, but there would be new responsibilities at the position he'd have to learn. And if we did do that, he'd have a whole spring and fall camp to get it down, but to go from playing outside to inside is a pretty big change to someone who's never done it. And going off how often we rotated players this season in the secondary, my point could be moot anyway.
2). He slowly been getting higher and higher draft grades. I think the average is he'll be taken in the 3rd round, but I know some have him going into the 2nd. If that gets to be the consistent consensus, then I think he leaves.
Im more than likely reading too much into this, and he does return. And if your sources are saying he is, then I'm taking your word on it. They've been right.... a lot.