I know that it is begining to sound like a broken record, but this time for sure. There is a good article in the today's Guard regarding this story. The final plans will become public in April. Here is a quote from CEO and President of the University of Oregon Foundation, Paul Weinhold.
Weinhold said a design for Hayward Field has been agreed upon with just minor details still to be worked out. He anticipated a public unveiling in April. “I do believe this will be the best track and field venue in the world,” Weinhold said. “I really believe that.” Even an expanded Hayward Field will be the smallest venue to host the world championships. Last summer in London, a record-setting 705,000 tickets were sold, and in 2019, the meet in Doha, Qatar, will be held in 48,000-seat Khalifa International Stadium