I don't think this is true, class 2 e-bikes are allowed a thumb throttle up to 20mph

This is a Class 3, so it needs pedals to hit 28mph. It also has a throttle up to 20mph for class 2 operation.

That's not how the regulation works. You can't have a multi-class bicycle. It can either have a throttle, or it can exceed 20, but not both.

Apparently Californa requires a label for what class the bike is[1]. I have never seen such a label on an e-bike and I've seen a lot of e-bikes in CA.

1: https://leginfo.legislature.ca.gov/faces/codes_displaySectio... (312.5.c)

There are just a lot of illegal Chinese electric motorcycles on the roads in California. That doesn't make them e-bikes though.

I stand corrected. I did not know that class 2 allows for throttle-only operation.