E2E Encryption is on the road map for Bluesky as it requires some protocol changes. The devs are encouraging people to use the DMs to exchange Signal info, and reminding people to not use DMs for sensitive info.
It wouldn't matter if they implemented "E2E" encryption. "E2E" is necessary but insufficient for messaging security. It would still be a terrible idea to rely on Bluesky DM's, even if they met some floor of cryptographic quality, for the same reason that it's a bad idea to use Facebook DMs, despite their cryptography being close to the gold standard for large scale social apps.
https://bsky.app/profile/pfrazee.com/post/3kt457v6aq72n