"Mistresses" Season 4 is not yet confirmed! But here's a spoiler, in case the show's next season happens!
Cliffhangers are the worst in TV series! It's not easy to deal with curiosity especially when TV shows are also at risk of cancellations. As per "Mistresses," the showrunners decided to end it with a cliffhanger and they just hoped that a new season will come up.
However, this cliffhanger may have caused fans to expect that a "Mistresses" season 4 is coming up. The producers of the show, however, are yet to be informed by ABC about the destiny of the show. The showrunners K.J. Steinberg and Rina Mimoun said that they thought twice about ending "Mistresses" Season 3 with Calista held at gunpoint by Wilson. However, ending it with her getting the 911 phone call or if Harry Tracked Calista, the result might be not as satisfying. This is why the showrunners said that they have decided to commit to their storytelling style and gave in to doing a cliffhanger, and simply hope that a season 4 would be given to them
The producers also said that if the show was to be cancelled, they would have definitely put in a different ending to season 3. Mimoun also said that they are not the type of showrunners who would make fans dwell in curiosity, guessing what the show's ending would be. She said that giving fans a sufficient finale is a priority for them. The show actually did well. It was even named as the top 2 scripted drama, next to "Under The Dome", among people aged 18 to 49.
Nonetheless, one thing is certain about the story of Mistresses. It was pointed out that Esposito won't be coming back to the show. Her character Calista was simply meant to join the story for just one season. Even though she contributed a stellar performance to the show, the producers are firm in introducing a new cast member instead.
So, just basing on everything we know about "Mistresses," we can assume that the show is good enough to get a new season. But then again, TV networks can just go ahead and cancel shows as they like, and we have seen them horribly do just that. We can only hope that a "Mistresses" Season 4 would be a thing in the coming months. If not, let's just use our crazy imaginations and come up with our own ending instead!