Hi Leonidas,
The Immortals are completely legal to use in all USBC sanctioned events. revTrex was correct, in that if we tried to submit a ball like the Immortals for approval now, they would be rejected by the USBC. However, since these balls were submitted prior to the rule change, it was grandfathered in, and can be used in anything that is not a PBA governed event.
Jason Wonders
Visionary Bowling Products