LastPass claims (right on their homepage) "Your data is encrypted and decrypted at the device level. Data stored in your vault is kept secret, even from LastPass. Your master password, and the keys used to encrypt and decrypt data, are never sent to LastPass’ servers, and are never accessible by LastPass." If that's accurate, they could only provide encrypted data to any authorities, which should be useless to them.
That said.... corporations lie, and software has bugs. I would be disappointed and angry to learn that authorities were able to collect usable passwords from LastPass, but I wouldn't be shocked. And of course, lol, that could already be happening and we know nothing about it. Or there could be a massive breach that we don't learn about for months. I no longer believe in "guarantees".