Salary less than Prevailing wage

Hi Team,

Here is the scenario, due to recent conditions ,overall economic issues and low revenue, my friends company is proposing temporary salary reduction.
So new salary will be around 15% less than existing and also it will be less than the prevailing wage for year.
So below are the 2 queries:
1)will there be any issue for my friend, as his total yearly wage will be less than prevailing wage?
2) Does his employer need to inform USCIS and file amendment or new LCA?

Thanks in advance.