If I'm not mistaken, I read that Brie Bella already announced her in-ring retirement on one of this season's episodes of Total Bellas, which was probably filmed at least 3 months ago but she's retired all the same. According to reports, Nikki Bella announced her in-ring retirement on last night's episode. Brie and Nikki are both still young women at age 35 so it's not as if they're over the hill; Beth Phoenix was only about 31 or 32 when she hung it up and it looks like she's back, at least for a while. After all, retirement in pro wrestling doesn't necessarily mean "retirement" as I've little doubt WWE would welcome them back if they wanted to return or to wrestle every so often at big shows.
I think that Brie is less likely to return as she seems to be fully content with her career and being a mother, I've read rumors that she wants more children but take that for what it's worth, and lots of reports came out about her last run in regards to how embarrassed she was about it. Brie never really was exactly world class inside the ring, but her last run in WWE was the worst she's ever looked by far. The extremely weak, half hearted and botched suicide dives she tried to do just made her look incompetent and giving Liv Morgan a concussion certainly didn't help either. Nikki used to be pretty decent but it was obvious she wasn't really in great ring shape herself, she was better than Brie but that's like saying being in a vegetative state is living a full life.
In a few years, they'll wind up in the WWE Hall of Fame, WWE will have this whole marketing campaign about how they were pioneers, trailblazers for the Women's Evolution and all that sorta nonsense that hardly anyone will really buy into seeing as how they thrived during the Diva Era, but whatever.