[ReidZB]

I don't expect there to be a similar community reaction. NIST and the PHC panelists (list at https://password-hashing.net/) are two very different bodies.

Argon2's internals will likely be altered (with community input); Keccak's internals were left alone (only parameters were tweaked).

The community wants modifications to Argon2 before its final publication. Essentially, each of the five supreme finalists possess nifty properties. It'd be nice if Argon2 could be modified to possibly have some of these too.

That being said, I do expect you're correct that the winner will not be in mainstream production for a couple years at least.