Heh, it's a bit confusing. The bill would go into affect at the start of 2017. The 2019 reference means that Section 2. would replace Section 1 in 2019.
What you're interested in are the Section 1 amendments.
"This bill, until January 1, 2019, would also exempt from the biennial smog check inspections all motor vehicles manufactured after the 1976 model year but prior to the 1981 model year if the owner submits proof that the motor vehicle is insured as a collector motor vehicle."
In 2019, then Section 2 takes into affect.
I believe the change that allowed the bill to get this far is:
"(3) The motor vehicle complies with the exhaust emissions standards for that motor vehicle’s class and model year, as prescribed by the department, and the motor vehicle passes a functional inspection of the fuel cap and a visual inspection for liquid fuel leaks."
So the visual test is practically eliminated. This would (supposedly) allow the owner to swap air intakes, cylinder heads, etc...as long as the vehicle passes smog (at the tail pipe), doesn't leak & fuel cap keeps pressure.