iFixit:

But over the weekend some brave Apple fans introduced their new iPhones to a life aquatic. The phones didn’t always emerge unscathed, but the overall trend is clear: the 6s and 6s Plus are dramatically less prone to liquid damage than their predecessors. (They aren’t, of course, completely waterproof—so don’t jump into a pool with them or anything.) […]

So, there are still places for water to get into the case. Maybe that strip of goo around the display isn’t for waterproofing after all, but has some other nefarious purpose; 3D Touch is a new technology, so it’s hard to say. Nevertheless, we think this is an exciting step forward for the iPhone and its fans.

I think Apple’s decision to stealth-upgrade the iPhone’s waterproof capabilities is extremely smart. Making the iPhone more resilient to spills is an incredible feature, but if Apple were to laud it as a tentpole feature, they run the risk of having users treat their iPhones carelessly. Apple wants the iPhone to survive more water incidents, but you don’t want users to get the wrong idea about using their iPhone in and around water — it’s probably still not a great idea.