I followed the instructions in the below linked thread to setup ADB/Fastboot commands on my new 13" MacBook Pro w/touch bar, just as I did on all my previous Macs. After doing the setup ADB recognizes and communicates with my Google Pixel with no issues. However, as soon as I type "fastboot devices" in terminal the whole computer locks up and becomes unresponsive until I manually power it off and turn it back on.
I tried going through the setup a couple of times to no avail. I even did a clean install of Mac OS on the machine and tried it again with the same result.
Now, here is the interesting part. I initially bought a 2016 13" MacBook Pro without the touch bar and used the same setup method to get ADB and Fastboot working. ADB and Fastboot commands performed flawlessly on that machine. But I decided to exchange the non-touch bar version for the higher spec'd one with the touch bar. It's only with the touch bar version of the computer that Fastboot commands lock it up.
At this point, I'm stumped. I don't know what it is about the touch bar version of the MacBook Pro that prevents Fastboot from working.
ADB/Fastboot setup for OSX thread:
Workaround: Installing Parallels + Windows 10 and setting up ADB/Fastboot within the Windows VM allows you to successfully run all ADB and Fastboot commands.