The "Advanced Clean Trucks" proposal has been approved and is scheduled to begin going into effect with model year '24. This initial rollout primarily affects drayage vehicles (shipping into and out of ports and railroad yards) and public fleets.

As California, so the nation: 5 other states have implemented their own version of the same rule as of question creation.

Industry and public organizations are concerned about the lack of available vehicles that meet the requirements, the lack of charging infrastructure, and a lack of cost projections associated with operating the fleets.

Will the new rule be successfully implemented as written when approved by the EPA in Spring '23?

The following sorts of events will cause a "No" resolution:
1. Delay or neutering of the '24 implementation requirements, including changes from "mandatory" to "incentivized"
2. Significant crash in new vehicle sales to the affected entities; sustained 25% or more, increasing the danger on CA's roads from aging fleets

3. Significant increases to costs of shipping into CA compared to alternatives

4. Massive snarls in affected shipping hubs, significant unavailability of public services due to implementation problems, etc.

Otherwise, a largely successful rollout with or without growing pains will resolve "yes". I'm aware that industry groups will complain about this heavily regardless of how successful the rollout is, so their complaints will be discounted in favor of hard data like shipping delays and cost changes.

This is somewhat fuzzy, so I'll refrain from betting in this market. Resolution will be on or before 1 Jan '25 so we can see how it plays out for awhile.

Links:
CA Air Resources Board description:
https://ww2.arb.ca.gov/our-work/programs/advanced-clean-trucks/about
Notes on the rule:

https://mobilitynotes.com/californias-advanced-clean-trucks-regulation/

https://blogs.edf.org/energyexchange/2022/10/03/the-advanced-clean-fleets-rule-explained/