#8 Deathstroke knows Batman’s identity, but he doesn’t care.

One of the more fascinating trademarks of Deathstroke is his code of conduct and professionalism, excluding some of his Teen Titans portrayals. Yes, things get personal from time to time (more often than not with the Teen Titans and Green Arrow). But Wilson typically sees Batman as just an obstacle or job, not someone to deconstruct with backhanded tactics.
Keep in mind that Deathstroke is one of the smartest characters in the DC universe at the moment. He figured out that Dick Grayson is Nightwing on all his own after accepting a contract to kill him. And the only reason Nightwing is still alive is because Dick Grayson outbid the other guy. Against Batman, it would make good sense for the DCEU to use this as the character’s starting point, before delving into what makes him tick.