We are not alone NZ and EASA require them to be carried out.
Cessna issued them as a Maintenance Manual revision rather than an SB, they are not a stand alone document like the previous CAPs.
It's the difference in our regs.
Even in the US if you did not comply and there was an incident that could be even remotely related the lawyers would have a field day, you may get off but the legal bill could be millions.