Obviously the concern is not the ASICs themselves but the ASIC designers. (Using miners here in the colloquial sense of human collectives/corporations backing the machines than than the specific sense of the raw machines themselves.)

Yes, a practical preimage weakness in SHA-256 is a nightmare scenario with huge implications to the rest of internet security beyond just get. It's why I sometimes can't sleep at night knowing how much energy bitcoin spends daily on a continuous massively distributed partial preimage attack on SHA-256.