The core fingerprint stack has landed in Cosmic with fprintd and libfprint being promoted to the main archive. Fingerprints can be used to unlock a session which has already been logged in to, not to log you in to a new session. This is a security consideration since fingerprints are considered to be equivalent to usernames, not passwords. As users can already chose to automatically login or opt not to have to unlock the screen with a password, fingerprints are equivalent here. Note that you will still need to have drivers for you fingerprint reader to make full use of this.
Ну собсно все как ожидалось.