NWSL Commissioner Jessica Berman confirmed in September that the league would move away from formal bidding processes to a rolling expansion model, allowing greater flexibility in adding new markets.
"Those conversations are ongoing," Berman said, according to ESPN. "Each of them has a different perspective on how much time they need to launch, the investments they need to make to be successful, including potentially around infrastructure, and we want to not force a square peg into a round hole."
Berman has repeatedly stated that the NWSL could eventually grow to match the NFL's 32-team structure.
"Our board believes that we can be the size of the NFL, there is nothing that stands in the way of us doing that, other than having access to top talent,” Berman said to Yahoo Sports. “There's certainly not a problem with the supply, given the size of our country and the level of talent that exists."