I'm no pro unlike those scary EXO-L investigators but I do have a small guess about the comeback...

In the Pathcodes, each one of the members is regaining their power.
But they're all also running away from something, and that something may be that they are to meet each other in Chicago as it you can hear in Suho's Pathcode at around 0:34 (!!!)
I believe that when they all meet, a comet or something will come and take them back to EXO Planet.

Now I also found a few clues from fellow investegators;

Call Me Baby has ten letters.
C 
A - Arizona (Chanyeol) 
L - London (Kai) 
L
M
E - Edinburgh (?)
B - Barcelona (Tao)
A
B - Berlin (Xiumin)
Y

there's a cab next to sehun and it show '02 JEO'
JEO means Just Ease Off.
02 represents 2 members who left exo (Luhan and Kris)
when you put it all together, SM's trying to say, "2 members who just went of easily" or "Just Ease off because we don't need you anymore"

"Apparently the two kids represent Kris and Luhan, the toys floating around was Luhan's power telekenesis and the plane represents flight which was Kris' power. Sehun leaves the two kids behind, those two are stuck and trapped, they can't mature meanwhile Sehun matures. After Sehun leaves you can't see the kids reflection on the door, meaning that the two and no longer part of EXO." 

[ THE LAST TWO STUNG A BIT :'( ^^ ]