Every system you mentioned other than Bitcoin already supports alternatives to SHA-256. There'd be a scramble for sure, but no different than the current steady stream of OpenSSL vulns. Probably less of a scramble than many OpenSSL vulns as SHA-256 could often be disabled via simple config file changes.
Bitcoin on the other hand would have to fundamentally change due to miners with ASICs. The code change might be minimal, but the economic, political, and psychological impact would be huge. For miners to lose their entire infrastructure investment in ASICs may cause an unrecoverable drop in hash rate as it takes 2 weeks for difficulty to recalculate.
Bitcoin on the other hand would have to fundamentally change due to miners with ASICs. The code change might be minimal, but the economic, political, and psychological impact would be huge. For miners to lose their entire infrastructure investment in ASICs may cause an unrecoverable drop in hash rate as it takes 2 weeks for difficulty to recalculate.