Sorry, this is old news. This has to do with a consent decree the MoCo was forced to sign with the EPA in July 2017. This why all of the Screaming Eagle engine and exhaust accessories now meet EPA standards.
https://www.reuters.com/article/us-usa-harleydavidson-emissions-idUSKBN1A41UU
The ARB (formerly known as the CARB) has always been "this way". Gov Ahnold signed a law about modification back in 2012 that made things even worse. The newest proposal being kicked around is to make all off-road vehicle conform to on-road ARB standards by 2027. This would effectively kill the OHV industry in Commifornia. Which, BTW, is being strangled by road and trail closures throughout the state, which is being copied throughout the Western US.
If you think any of this stuff has anything to do with a cleaner environment, I'll sell you a bridge cheap.