I'm pretty sure Disney will make sure that copyright laws keep getting changed.
I was talking more about the Seigel family, who have never missed an opportunity to squeeze Warner Bros. for a few more dollars whenever their lawyers see an opening. Yes, they have settled the case currently, but there's no guarantee that they couldn't try again thanks to the clearly shady behavior of National Comics back in the 1930s and 40s that allowed Seigel and his heirs to keep the issue of Superman's ownership a reoccurring thorn in the side of Warners since they bought DC decades ago.
Unlike Batman & Wonder Woman, I don't think the ownership of Superman is as cut and dried, even after this latest settlement. There have been settlements before, so I don't think there's any guarantee that the Seigel estate can't try again and again if some legal precedent presents itself. As a result, shifting the Superman franchise towards Jonathan Kent, who Warners owns without any legal complications would be a smart move on their part. If they can establish Jonathan Kent as a stand-alone character beyond his parents, then Warners has a far better position to negotiate from moving forward.
Look at Future State: Superman of Metropolis as a good example. There's virtually nothing in there that isn't fully owned by Warner Bros. Lois & Clark are absent, along with the main elements of the costume seen in Action Comics #1 are all gone. There's almost nothing derivative (from a legal standpoint) left that the Seigel estate could latch onto.
I don't know. I could be completely off-base here, but the speed in which Jonathan Kent went from his creation to the main character seems a little too fast, so my Spidey-sense is tingling. It's entirely possible that this is simply more creative flailing around on the part of DC, who still don't know how to make the character relevant to today's audiences.
I mean, the story of a refugee raised to love his adoptive planet and works to protect it with his alien abilities while working to expose the corruption of the rich and powerful as a mild-mannered reporter just doesn't seem like something that would
resonate with today's audiences who are living in a world that shares so many similarities to 1930s America.