Huh. I was expecting the "mysterious Tomorrow Man" to be Jon Kent ever since I saw the issue cover a few months ago, purely because of the symbol on his chest. You know, the one that looks very much like Dick Grayson's Nightwing. Dick Grayson, who was Jon's mentor for a long while now (though mostly off-panel), and whose hero identity – Nightwing – is a Superman legacy name, from Kryptonian culture.
Jon's suit in Superman Unlimited #11
Issue title in Nightwing (1996) #1
This version of Dick's symbol was part of his suit design in various forms until the birdified logo was introduced in Rebirth.
Gotham Knights #10
Nightwing (1996) #113
Nightwing (2011) #16
(The shape is also used in his mask, as well as wing-dings.)
Interestingly, other Nightwings (almost always) used completely different symbols.
Instead, the origin of Jon's suit is that he takes it from one of the soldiers from the future:
Superman Unlimited #11
Which. Huh. I wonder if we'll get an origin of those suits. They may still be connected to the Nightwing (or, likely, Flamebird. Since. You know. Yellow.) symbol. Maybe it's a time paradox thing.
Or maybe it's a pure coincidence. We'll see ¯\_(ツ)_/¯
