Well according to this support document from apple: "MacBook (Retina, 12-inch, Early 2016) and late-2016 MacBook Pro models support 60Hz refresh rates over HDMI when used with a supported HDMI 2.0 display, an HDMI Premium Certified cable, and a supported USB-C to HDMI 2.0 adapter."
from: Using 4K displays, 5K displays, and Ultra HD TVs with your Mac - Apple Support
We are trying to figure out what hdmi adaptor can used. I received an email from the uptap (manufacturer of https://www.amazon.com/gp/product/B01DPY6AN8) that they are working on a firmware update to fix the support issue but no time frame on the release!!
sgacanovic wrote:
I was going to buy Google's USB-C to Displayport adapter cause it does 4k @60hz no problem, but the issue is my work requires me to plug into tvs that only have HDMI ports on them... And it looks like there is no 4k @60hz HDMI option that works for the new macbook pros right now