Only 3 seasons and it’s cancelled.
According to WeGotThisCovered:
Batwoman had to overcome a major obstacle after its debut season. Ruby Rose stepped away from the title role, leading The CW to somewhat reboot the DC show for its second year, with Javicia Leslie hired as new heroine Ryan Wilder. Leslie has been embraced by Arrowverse fans, but unfortunately ratings have not been kind. And while a third season has already been commissioned, the latest intel is saying that that could be it for the Gotham-set series.
Giant Freakin Robot has heard from their sources that, at this stage, The CW is planning on Batwoman season 3 being the last run. This echoes similar information shared by tipster Daniel Richtman earlier this year, which pointed to the exact same thing happening. That’s disappointing to hear, of course, but there is a silver lining, as GFR also writes that the network fully intends to bring back Ryan Wilder elsewhere in the Arrowverse.
The outlet is unable to say, however, in what form the Scarlet Knight could continue on after the cancellation of her own show. That means there’s a small chance she could be moved over to a different series as a regular – how about Batwoman hopping aboard the Waverider on Legends of Tomorrow? – but it’s probably more likely that she would appear in a guest capacity in crossover events. In fact, they could be thinking of doing something comparable to Diggle’s upcoming return.