It's possible that all of this connects to the Arrowverse, but if it is, it all seems ill thought out.
It's a hodgepodge mess of TV actors being setup for movie roles, and letting the CWTV crew do all the universe building and trying to wedge that into the movie cannon afterwards.
I would just think that with DC having full control of all their characters and having a major studio such as WB as their parent company, and the CW as their own TV station, they would have an actual plan in place. But nothing seems connected, half of the selected properties being brought to TV are quite obscure and the other half potentially conflict with Movieverses plans for the JLU movie.
(The Flash & Nightwing being cast on Arrow, The CW developing Amazon - yet WB is casting Diana for the BvS movie)
Arrowverse is rapidly expanding and may just engulf everything, but if that is the case, then I hope a WB/DC universe overseer steps in to keep everything on a cohesive flow, outline an actual plan/direction and have a hand in casting (so that actors being chosen for TV can be groomed for movie appearances too & vice versa).
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Arrow - This = Universe central. The Arrowverse. this is where the current focus is.
Gotham - This takes place with a young Gordon before Bats. Can't directly connect to current MoS if Bats is now in his 40's, unless they use this as an origin story for a young Batman, 15 or so years before MoS2/BvS
Constantine - Kinda obscure, but people may remember the movie. Introducing a supernatural element.
Hourman - Very obscure.
The Flash - Will he be The Flash they wanted for the movie? If not, they may just decide to have 2 universes.
You forgot:
Amazon - This could be the origin series for whoever is chosen to play Diana. Introduce her in the movie and then start the TV series afterwards.
The Avenger - another very obscure character who will likely need a name change.