Maybe Apple jumped the gun a little soon, however, there are docs you can get that include SD along with USB-A ports and etc. available.
there are docs available from various manufacturers, including this USB-C doc:
https://eshop.macsales.com/shop/usb-c/owc/usb-c-dock
...
As far as the optical audio port goes, (as I already stated in this thread), that audio codec is outdated, unfortunately, as no industry supports it any longer, (it is only limited by the electronics on either end, fiber optics are used in the fastest ethernet networks, and are used for longer TB cabling, not to mention Gb internet. In fact, the TB standard, as originally written years ago, called for optic cables for 100Gb speeds.). It has been pointed out that a main reason for this is because power requires copper cable, however, I do believe it is possible to drive power optically, but, no one is developing because of fiber optic cable cost and the copper industry's push to stay valid.
Now you get lossless audio through DisplayPort (via TB3/USB-C port) or HDMI. Personally, I think the TV/Video industry needs to adopt USB-C/TB3 connections as well, TB3 has enough throughput to drive lossless audio and UHD video with WCG & HDR, (DisplayPort (implemented here at 1.2, I think.), is also part of this standard USB-C connection, supports UHD/4K, but, not sure if at 60fps. The 5K LG monitor Apple's promoting actually uses TB3 over the USB-C connection, for single cable connection. Other 5K monitors require two DP or USB-C cables.). HDMI 2.0a uses video compression to drive UHD, if I'm not mistaken.
The positive side of USB-C ports is that they support multiple kinds of connections: data, audio, DisplayPort, ethernet, and in combination with TB3 in this case: 40Gb data transfer rates and PCIe expansion. So it's not just a data connection, like USB 3.0 and earlier. You can also charge your MBP just by connecting to a device that is plugged-in, and on any port, as power can go in both directions over USB-C and up to 100 watts. USB-C also doesn't matter which way you plug it in, can't be trying to plug it in upside down, and the plugs fit better...I have too many loose connections w/USB-A.