What do you mean by safe?

Hypothetically (not suggesting anybody has suggested this), but wouldnt a softfork (or hardfork) be able to freeze a specific set of addresses? so KYC can be added to bitcoin via softfork and only the majority of hashpower needs to be bought/convinced to conduct this softfork attack

Since a hardfork is much more visible and requires buyin by the community at large, the softfork attack appears to be much more of a threat than a hardfork attack, but if all the miners switched to a KYC version, along with all the big companies, then this seems a pretty viable attack vector, even as a hardfork.

James