If you rotate verification method, all previous FEP-8b32 proofs become unverifiable. Does this count as repudiation?
this could work but only if the rotation was a "blind rotation", i.e. without a verifiable log of the old key being associated with the identity. if there is a log of the key rotation, then no.
more pressingly, if the key is your identity, then it cannot be rotated without also fundamentally changing your identity. so key rotation with repudiation requires a non-key identity -- in other words, a name (and authoritative name server) or description (and a way of asserting trusted claims that match the description).
silverpill:Additionally, some cryptographic tricks may exist that enable repudiable signatures, for example I was able to find this paper: https://dl.acm.org/doi/10.1145/3659467.3659901
from what i understood of the paper, it seems this is just delegating signatures to some authority who can sign things on your behalf. you can then claim the authority forged signatures on your behalf. it's basically like how fedi uses custodial keys in most cases.