It had been previously rumored that Apple is replacing the headphone jack with a second speaker, but now it seems like it's simply redesigning the microphone port to look like a speaker port, according to leaked schematics obtained by notorious gadgets leaker Steve Hemmerstoffer that were first spotted by MacRumors.
Steve Hemmerstoffer/nowhereelse.fr
Hemmerstoffer also speculates that adding several holes to the microphone port serves only a cosmetic purpose. That way, the iPhone's bottom edge could appear more symmetrical. It means that only one of the holes could serve as the microphone port, and the others have no function at all.
Indeed, the microphone port on the iPhone 6s is made up of only one hole.
Austin Evans/YouTube
A supposed iPhone 7 dummy on the left shows two speaker ports. The iPhone 6s is on the right.
A second speaker could have potentially filled in the space leftover by the allegedly missing headphone jack, but now it's unclear what parts could fill in that space, as microphones on phones traditionally don't take up as much space as a speaker.
We have no real way of knowing whether any of these leaks and rumors are true until Apple unveils the iPhone 7 during its Fall iPhone event, which is supposedly happening on September 7.
This mystery is another reason why Apple's iPhone event will be very interesting despite the possibility that it could look nearly identical to the iPhone 6s.