They're planning to bury 10k miles of electric lines, at a price tag of $15-$30B (they have 5.5m customer accounts).
https://www.washingtonpost.com/nation/2021/07/22/pge-power-l...
https://www.washingtonpost.com/nation/2021/07/22/pge-power-l...
We're mostly seeing service disruptions from downed lines and not wildfires though. Fire safety requirements might be grounds for general funds to pay for undergrounding, but you'd really need to check with the state regulations.