Yeah it's not new. The chat feature has existed for a short while, too, which deserves more fame as being an e2e encrypted multi-device IM system that isn't tied to your phone number.
On the other hand, it doesn't feature forward secrecy.
(by signal public key I mean that your safety number with any given person is always a concatenation of a string that identifies you and a string that identifies them and you'll find that same string across your safety numbers with all your contacts)