Harley Quinn Boss Discusses DC Comedy’s Future, As Season 5 Finale Serves Up Much Closure
'Harley Quinn' Renewed or Cancelled — Season 5 Finale Explained
I suspect many of DCs future projects depend on James Gunn/Peter Safran and the DCU. Even though Harley Quinn is outside of the DCU, as the head of DC Studios it's technically under Gunn/Safran.
If Superman does well in July I expect we'll see the series renewed. If not, it's probably over.
I'm sure Gunn/Safran would renew it now if they could, but money is probably still a bit tight.