For wifi, I confirm that the following image (http://mirror.centos.org/altarch/7/isos/armhfp/CentOS-Userland-7-armv7hl-Min...) has the /root/README file.
I got it from http://buildlogs.centos.org/centos/7/isos/armhfp/CentOS-Userland-7-armv7hl-M...
But the /root/README is about something else. I googled and found the firmware on a Fedora site, same file names.
I put the 1603 (instead of 1602) in my download queue and made a note to check there for a new version before downloading. It might be a week or so.