A low-carbon fuel standard (LCFS) is a rule enacted to reduce carbon intensity in transportation fuels as compared to conventional petroleum fuels, such as gasoline and diesel.
It is a good but general question. The future of LCF standard and the impact of EVs depend on the countries and their policies. Many countries may follow the standard, but the others may ignore it. For example, take a look at the following references. Ref. [1] belongs to a study in Malta, while [2] studies the developing countries.
[1] von Brockdorff, Philip, and Gerald Tanti. "Carbon emissions of plug-in electric vehicles in Malta: A policy review." Case Studies on Transport Policy 5.3 (2017): 509-517.
[2] Onn, Chiu Chuen, et al. "Greenhouse gas emissions associated with electric vehicle charging: The impact of electricity generation mix in a developing country." Transportation Research Part D: Transport and Environment (2017).
For electric cars, the carbon reduction depends on what types of energy that generate the electricity. If the electricity is generated from coal power plants, then it does not reduce the GHG emission...