I am with @Cimmerian101 here that the rumoured stylus slot may well be a headphone jack, unless Patently apple has some data along with the pics to suggest otherwise.
However, I do believe that surface phone (though I am sure it won't be called a 'phone') will have stylus support. After all what MS is after is not actually upgrading phone to do computing, but to squeeze its surface line into a 6" or less form factor that will have the option of calling. They are working backwards with this device and hence ditched the phone division which was about upgrading the phone.
Curiously the article missed upon the recent announcement that windows 10 will soon run on ARM. That was a very big hint about features of this upcoming device. It may still not sell a whole lot, but it is expected to turn Microsoft around in the mobile space.