The backstory they mention for Wilson doesn't seem to fit Arrowverse continuity. I guess they've given up on tying in animated webseries with that. Vixen was a close but imperfect fit, while Freedom Fighters: The Ray tried to be in the Arrowverse but ended up massively contradicting its version of the Ray and Earth-X (as well as having Mr. Terrific fly for some reason), and Constantine: City of Demons turned out to be completely unconnected to the NBC/Arrowverse version aside from starring Matt Ryan.
Hmm... City of Demons was essentially in continuity with Justice League Dark, which was in the larger DC animated-movie Batman/Justice League continuity. That has its own version of Deathstroke, voiced by Thomas Gibson in his first appearance and the late Miguel Ferrer in his second. I wonder if this might be in that continuity too.