I think DC's upcoming lenticular cover showing Jor-El is part of a misdirect on their part. Here's why I feel Jonathan Kent is Mr. Oz.
1. He refers to Superman as "Clark," not "Kal-El" as Jor-El would do or "Superman" as Ozymandias would do.
2. Oz says he "taught" Clark things. That seems more appropriate for Pa Kent to say rather than Jor-El as Jor-El played a minimal role in raising his son even if Kal-El didn't leave Krypton until he was two.
3. Finally, the biggest clue is Mr. Oz's name itself. Mr. Oz is NOT a reference to Ozymandias.
Mr. Oz
as in "The Wizard of Oz"
as in "transported from Kansas"!
It's possible that Ozymandias is involved in Doomsday Clock as part of a war between him and Dr. Manhattan, but I just don't see Mr. Oz as being Ozymandias, and really, there's no way that DC would allow Jor-El to be alive. Marvel would sooner bring back Uncle Ben.
Anyway, I think, based on my reasons above, Mr. Oz being Pa Kent is one of those "staring you right in the face" things that we tend not to notice. I wouldn't even be surprised to learn that it was DC who leaked the spoilers to Bleeding Cool regarding Mr. Oz being Jor-El.
So what do you guys think? Is it more likely to you that Mr. Oz is Pa Kent?