I believe if there was that direct threat from the Chinese government, a POW change is in the discussion.
Such a POW change is not a cut and dried decision. To some, it would indicate the ultimate failure of Bitcoin's economic model. And ousting SHA256 miners would effectively pull the rug out from underneath the economy. A blockchain split would be inevitable and the security of the forked chain would be highly questionable.
It'd be interesting to see how that would play out, but it's not something I hope for. In that sense, maybe it's a good thing that
local authorities are pressuring Sichuan miners to scale down.
How would mitigating a direct catastrophic threat be an "ultimate failure" if the mitigation is what would actually save the network/protocol?
But, ultimately, I believe the threat/fear of a POW change will cause miners to sort themselves out. Their interests are tied directly to the network/protocol.
Miner's interests are tied to the ASIC infrastructure they have built,
their are at least 3 major coins, they can support or switch too.
Thinking they have any loyalty to any coin is a opinion not a fact.
Their loyalty lies with their personal hardware infrastructure and whichever coin provides the highest profit margin in their own opinion.
Due to the reward drop this year and the majority of fees moving to LN, Bitcoin status as the most profitable could decline verses the others.
As in any conflict, best interests and support will change with different conditions.