It's not a good plan. They propose to design, de novo, in an open standards group, a cryptographic secure group messaging protocol based on a design that has never been deployed at any scale. The underlying design is cool --- it's basically Asynchronous Ratcheting Trees, which was presented in a paper at RWC just a few weeks ago. That's how de novo this particular "standards" effort is: the underlying theory is just 28 days old.

Already, in the starting point draft, it's been crudded up: it has "ciphersuites", and comes with support for the NIST P-256 curve --- despite the fact that the underlying design wants to take byte strings to curve points, which is tricky to do on the P-curve. It will only get worse from here. They'll figure out some reason to bolt a PAKE onto it soon enough.

Signal Protocol is exceedingly well-documented (and even before those documents were written, it was open enough for Wire to lift the protocol wholesale).

The IETF is bad at cryptography. Your default position should be distrust of IETF crypto standards.