For those who are legally required to be on record, there are other ways to keep track of the conversations for audit purposes without compromising the e2e encryption. For example, every room could have an audit bot invited by default, visible by the users, and which would record everything being said. Then you can setup the access to the logs from the audit bot to only be unencrypted in certain conditions, e.g. if the 2 halves of a key giving access to the account are put together. It's secure, clear for the users and legally compliant.
[disclaimer: I'm from the Element team]
