That that's the way it was before doesn't mean that's the way it has to be now. Proven by the fact that it isn't the way it is now. To work it the exact same way is predictable and boring, and its not like there's tons of room with these characters to be genuinely new in the first place. That's why you see some of these overbearing rules for characters like Superman and Wonder Woman particularly being dropped after the relaunch. Their iconic status led to an unfortunate look but don't touch mindset that hindered creativity. And again, with characters as old as they are, the last thing that needs to be done is to hamstring them further. Its hard enough. I'm just glad the tune has changed and their more lax with the possibilities and not holding to some rules just because it was that way before.
I have no more interest in knowing who the present day Superman will end up with for the rest of his life any more than I have any desire to know any other pertinent details that will never be fulfilled anyway in an ongoing continuity, like how and when he eventually dies, if he has children, and so on and so forth. That's the appeal of the ongoing, until they decide so time is endless and thus so should the possibilities within reason.