It's not Cedar Fair "protecting" or anything (If it were, why would they find it necessary to protect i305 when it wasn't a record-breaker in the first place?) because at East Coast Bash 2010 John Pagel said that it was Intamin who made the design to be 305ft, and that it was 305ft before they even ordered it.
Plus a B&M Giga and i305 are completely different experiences.