And there's no legal confusion over the rights to Lex Luthor or the Legion, without whom what's the point?

Well, it's entirely possible to keep the basics of the Superman origin only using Superboy as a young Superman, redefining his hero contacts and villains as necessary. Surely there's more than enough character ostensibly in the public domain to make Superboy's life interesting, without resorting to Luthor or the Legion.

I'm thinking about what Stan Lee and Jack Kirby did with the Silver Surfer in 1978, in the graphic novel they produced. The basics of the Surfer was kept, the extraneous stuff with the FF and Doom and the Defenders was subjugated, and the story still worked as a Surfer tale complete with everything you'd expect. This is how Superboy could be done...even Superboy in the future, since it isn't absolute essential that Superboy stay in direct contact with the Legion. You could make all of that stuff vague, turn Superboy into an honorary member and send him out with created-for-the-series "new" Legionnaires, like Atomic Lad and Pillowy Bosom Girl, on adventures.

I think DiDio was making a joke that Connor would stay dead until the legal issues got solved about Superboy. DC wins, Connor is back as Superboy. DC loses, Connor stays dead.