Suicide Set images have already revealed that Ben Affleck, Gotham City and Batman are involved, so Lex Luthor in a cameo appearance or some other capacity wouldn't be a big stretch (especially if WB is trying to interconnect all their movies).
Now Eisenberg addresses Suicide Squad while speaking with Total Film Magazine.
"I would love to," Eisenberg notes, with the article mentioning Jesse Eisenberg is not rulig out Suicide Squad. "It could be the start of something special."
Regarding Jesse Eisenberg's Lex Luthor in Batman Vs. Superman, Zack Snyder offered: "Jesse is going to be an amazing Lex" and "This guy is the real deal."
Eisenberg wouldn't offer much as well, but said: "I can't say anything about this stuff. They want it to be a surprise."
Batman Vs. Superman hits March 25, 2016 followed by "Suicide Squad" on August 5th.