As for the new Black Canary Dinah Drake (Juliana Harkavy), she’ll see her episode count at least double for Season 6, which doesn’t seem all that surprising in hindsight given the character she’s playing.
In terms of Arrow, Malcolm Merlyn would be a series regular.
So what’s the difference between a recurring character and series regular?
While he’s important to the story of Arrow, his appearances vary depending on the arc and his relevance to the plot.