Unfortunately, it will be up to state regulators to determine if E15 ends up at your local gas station. I sure wouldn't put that past the California AQCB. They just love anything that dilutes gasoline and refineries love any product that they can charge more for and blame the regulators for requiring it. I won't have to worry about any of that once I get my Empulse.
I just noticed protomech, that you have a Suzuki GS500F. My daughter had a 1990 GS500E and she put 85,000 miles on that bike in only 4 years. She had it while she was attending UCSD and would ride back to my home near SF on the weekends. Later she moved to Seattle and would ride from there to my home 17 hours non-stop to visit me on the weekend, too. Eventually, she sold the bike to a fellow from Mexico for $800 and he planned to ride it back to Mexico City. I hope he made it.
It was a great bike. All it needed was a washer under the carb needles to smooth out the power curve and at 45,000 miles. I have to to replace an oil seal behind the ignition pick-ups with a Honda item, as the original seal wore a groove in the shaft. The Honda part was a double seal and it rested against the shaft to either side of the area that was worn. That permanently solved that oil leak problem.