Yes, it could work in some situations. But the attacker could also add a failover. Or add a failover and wait. Two way verification with other networks would allow you to revoke and restore keys with higher confidence. We dont have a way to roll over keys, that all clients accept. And if something gets rushed through the NIPs we may be stuck with something that has weaknesses and hard to replace.

I like something like this, with OP_RETURNS, it tracks new keys.

https://nostr.directory/p/melvincarvalho