I wonder...really...could it?

It looks that way too me.

dont know

So it is then.

The whole DCAU

I don't know about Smallville , but I'm pretty sure DCAU is earth 12.

Earth 12 is the reality of Batman Beyond....whether that means that JL and JLU took place in it's past or not hasn't been said

Could be true

Well, it would be really weird to draw a universe that happens to be animated-looking.  A better representation would be to use a character that exists exclusively in the DCAU.  Aside from Terry, the only unique character I can think of is Tsukiri. But I doubt anyone would recognize her.  
 
Almost all the other DCAU originals have been absorbed into the mainline universe: Harley Quinn, Mercy, and so forth.

Well it could be earth 12, that's how I always saw it

With the new comic Superman/Batman Annual 4 Superman is wearing the same costume that he had in Batman Beyond and mentions the story that took place in the show he appeared in. Also when we are in the fortress it does look like the one in the animated series. There is some trouble though as we see past costumes on the drones in the fortress we see the costumes when Superman returns from the dead and when he was the energy Superman Blue. These did not happen in the animated universe from what I know. This could mean that this universe is like the animated universe but not the same one.

The DCAU takes place on Earth-992. It was shown in Man of Steel #37, during Zero Hour. Earth-12 is similar to Batman Beyond, but not necessarily to the rest of the DCAU. For example, Hal Jordan was a Green Lantern on Earth-12, the Green Lantern Corps only has seven members, and the current Green Lantern is not Kai-Ro. Also, Earth-12 may be where the Tim-Drake-in-a-Batman-Beyond-suit was from and may not even have a Terry McGinnis.

this is a late reply and I'm not sure if you're even active anymore but I have to address this

I don't know where you got your info from but there isn't any mention of Earth 992 or the animated universe in Man of Steel #37....DC had stated before Flash Point that Earth 12 was the DCAU and that Batman Beyond took place there....as for the Green Lantern stuff and the Tim Drake in a Batman Beyond suit stuff...I have absolutely no idea where you're getting that

@danhimself: I know that I'm replying to a comment that is two years old but do you have a link to an interview or a quote about that Flashpoint thing with DCAU and Earth 12 being one in the same. I just really wanna know because I love the DCAU and would love to know if that is truly a comic version, and I've learned with comics, if it can't be confirmed, it might as well not be true

I think the DCAU is Earth-12.