Without knowing the state, it is hard to evaluate the specific provision he is referring to. What he is likely describing is a parole eligibility window rather than an automatic sentence reduction. Some states do have provisions where inmates serving life sentences for certain offenses become eligible to apply for parole after serving a minimum number of years, often 10 to 15 depending on the offense and the sentencing structure.
The critical piece is whether the judge included a parole provision in the original Judgment and Commitment Order when sentencing. If parole was built into the sentence by the judge, then reaching the 10-year mark opens the door to apply for parole consideration. If the judge sentenced him to life without the possibility of parole, no bill or statute changes that without a court order modifying the sentence itself.
For a second-degree murder conviction specifically, parole eligibility varies significantly by state and by how the offense was classified and sentenced. This is not something that can be evaluated without knowing the state, the specific sentencing order, and how the relevant statute applies to his case.
The most reliable path to clarity is having his attorney or a post-conviction attorney pull the original Judgment and Commitment Order and identify exactly what parole provisions were included. The bill number he mentioned is also worth researching in the relevant state code to understand what it actually says versus how it is being described inside the facility.