User blog comment:Dman6233/OT Live Action Teen Titans Series to air on DC Digital Service and be produced by Arrowverse writer, Greg Berlanti in 2018/@comment-1330227-20170428070756/@comment-24152851-20170428071410

I'd think they will definitely have it on Earth-1. The only reason Supergirl was on a different Earth was because they used originally had extremely different continuities so the "alternate Earth" was used to explain that difference. If they start this off keeping it a shared universe then they should be fine.

I was thinking that for Slade too. Or maybe, Slade had history with Dick Grayson during the years he was a mercenary before getting back to Starling City.