Normally LastPass servers won't send out encrypted passwords unless the client proves it knows the master password. With the hashes leaked, does it become possible for an attacker to retrieve encrypted passwords (i.e. ciphertexts, which are useless without the master password) without first cracking the leaked hash to obtain the master key?
I realise that at this point LastPass won't send encrypted passwords to new IPs, but there must have been a window in which they would have. If this is possible, then we must assume that the attackers managed to pull at least some percentage of the encrypted passwords.
This would be bad news for anyone with a sub-optimal master password, because if there is any chance that it might fall to an offline attack then changing your master password alone won't help: you'd need to also change the actual passwords before your weak master password is cracked.
Conversely, if you don't think your master password can fall to an offline attack given what we know about the hashing algorithm, then there is no point in changing anything at all. The only scenario in which you would change your master password but not the actual passwords is if you believe that your ciphertexts didn't get downloaded by the attacker. Otherwise you either change everything or you change nothing.
Is this a plausible scenario? Would you expect that the attackers managed to retrieve some percentage of the encrypted password ciphertexts?