If you look at the specifications of the three new phones you can still see that they're rated to the same IP65/68 as the older versions (eg. Z5 Compact Specs, Z5 and Z5 premium). IMO these phones are just as waterproof as they ever were, some Sony lawyer just said "Hey, nonono you can't market it like that any more, we'll be liable if someone goes snorkeling with their phone and it leaks."