That’s pure historical revision. The sentencing difference was created in 1986 based on the belief that it was more addictive. It wasn’t until a decade later that research showed the causation had been reversed (more addicted people were more likely to use crack). If you look at the timing, there was a huge increase in drug crime that occurred as a result of the crack epidemic: https://www.nber.org/digest/oct18/lingering-lethal-toll-amer....

The recent change in policy simply reflects the prevailing trend of reducing disparities in sentencing for criminals while increasing disparities in crime victimization by failing to enforce the law.