MM,

it's not related. The "core lock" issue received attention after the Pinnacle guys flamed out both motors joining the "410 Club". Wikipedia has it short and not so sweet. The NTSB report is equally frustrating\irritating reading.
Pinnacle Airlines Flight 3701 - Wikipedia, the free encyclopedia

Think about it this way, if you lose a motor you need to have someway to keep it turning fast enough to restart it, don't keep it turning and you can wind up with cooling issues as different parts of metal shrink\contract at different rates. So basically, Pinnacle guys minimized their descent angle, minimzing the speed through the motors and froze the engines. Once they made it to an altitude where an APU start was available, there was no way they were going to get either motor running short of a miracle. Unfortunately, they hid the fact that they had lost both engines for long enough to put them behind the power curve. A wager they both lost.

The Ice Crystal phenom is something different. Basically, the atmosphere is different than the models and engines are encountering some conditons scientists once thought impossible.
Still, I'd be more worried about it if I was a 777 guy