So what does this mean?
For the DC shows, anything that was produced prior to 2018-19 season will still stay on Netflix like The Flash, Black Lightning and Arrow until they end.
However, new shows like the upcoming Batwoman will be shopped. Meaning it could go to Netflix if they are willing to buy it or it could go to Hulu , WB service or even here.
Basically anything new from here on out that airs on that network will no longer be exclusive to Netflix.