‘Today we are happy to announce the first step in advancing quantum resistance for the Signal Protocol: an upgrade to the X3DH specification which we are calling PQXDH. With this upgrade, we are adding a layer of protection against the threat of a quantum computer being built in the future that is powerful enough to break current encryption standards.’
Also remember that this is only a layer of added protection. Work on this will continue. But this is more than what any other player in this market space currently offers.