Z5 Premium waterproofing may not be what you expected

I'm very disappointed at the moment. I currently have a Z3 Compact, whose waterproofing disclaimer stated:

Quote:

*The Xperia Z3 is waterproof and protected against dust as long as you follow a few simple instructions: all ports and attached covers are firmly closed; you can’t take the phone deeper than 1.5m of water and for longer than 30 minutes; and the water should be fresh water. Casual use in chlorinated pools is permitted provided it’s rinsed in fresh water afterwards. No seawater and no salt water pools. Abuse and improper use of device will invalidate warranty. The phone has an Ingress Protection rating of IP65 and IP68.

Now however, on the Z5 Premium official page, the disclaimer states:

Quote:

**** The Xperia Z5 Premium is waterproof and protected against dust, so don’t worry if you get caught in the rain or want to wash off dirt under a tap, but remember: all ports and attached covers should be firmly closed. You should not put the device completely underwater or expose it to seawater, salt water, chlorinated water or liquids such as drinks. Abuse and improper use of device will invalidate warranty. The device has Ingress Protection rating IP65/68.

What they're describing is a water-resistant phone, not waterproof. I'd like to ask Sony if it was really worth it to put the usb port outside the flap and lose the possibility to use the phone underwater like I always did.