Noob here.

What about NIP41 requires centralization? The announcement of the revocation? If so, could we remove the requirement for announcement?

Could NIP41 suggest generating something like 12000 keys (1 per month for 100 years) instead of the proposed 256 in the NIP? Then everyone rotates on the first of the month if they want to? 
Too much processing on onboarding or recovery? Or too much of a pain for each client to download the list of 1200 keys for each of their contacts? If that’s too much then rotate yearly Puts the burden on clients, not relays (except load) or Nostr code. Remain backwards compatible for all existing keys. Clients could choose to care or not about rotated out keys. Clients could say “outdated contact, use caution” etc.