Sunday night marks the end of the 30-day extension for negotiations involving the new WNBA CBA. However, the league and the players' union have yet to announce the finalization of a new CBA, with revenue sharing and salary increase being two sticking points in the negotiations.
It's possible that both parties could agree to another extension if CBA talks continue to stall. However, there are major consequences that could unfold if the WNBA and WNBPA still can't get on the same page.
WNBA CBA extension deadline: 3 major consequences if no deal is reached over salary increase
Major events on the WNBA's calendar could get delayed

As reported by Madeline Kenney of The New York Post, certain events on the WNBA's calendar will be put on hold until a new WNBA CBA is agreed upon. These events include expansion drafts for the incoming teams Toronto Tempo and Portland Fire, free agency, and annual WNBA draft.
Though the WNBA draft for players coming out of college is typically scheduled in April, a delay in the schedule for either expansion draft would compromise the preparations of the Tempo and Fire organizations. Also, the rosters of all WNBA teams would be up in the air as well if the free agency period gets pushed back.
The WNBA gets bad PR while other leagues can look good

The longer the wait for a new WNBA CBA, the bigger the PR hit that the WNBA will take. With other players' associations expressing their solidarity with the WNBPA, the WNBA is under a lot of pressure to reach an agreement with its players.
If the WNBA fails to do this, other leagues like Unrivaled and the so-called "Project B" can step in and project themselves as organizations that take better care of the athletes. During the inaugural season of Unrivaled earlier this year, the significantly better salaries and benefits that its players received were cast in the spotlight. These perks will be underscored even more if the WNBA CBA remains in limbo.
The league and its players will move one step closer to work stoppage

On the one hand, it doesn't appear likely at this point that the WNBA will lock its players out, given the tremendous popularity of its biggest stars like Caitlin Clark, Angel Reese, and Paige Bueckers. On the other hand, the scenario of a lockout remains plausible so long as a new WNBA CBA isn't finalized. The players can also opt to go on strike if the league continues to disagree on salient issues like salary increase.