Health Insurance Blue Shield of CA PPO vs EPO

Rarely got sick earlier, thought I'd get the better insurance plan next year due to COVID. Previously on Blue shield PPO, transferred to EPO since it costs more..later found out EPO only covers in-network services, even if it has lower out-of-pocket and deductible.

The question is
1. does all hospitals in-network would accept both PPO & EPO? This would be my impression, except I checked UCSF coverage (https://www.ucsfhealth.org/billing-and-insurance/health-insurance), and it only shows PPO, not EPO
2. CA law allows you to change plan until Jan of next year, yet the insurance company refuse to update my insurance (dd 11/15). Is this legal?