I have replied.

There is no such thing as a HDMI 2 cable. http://www.techradar.com/news/television/hdtv/hdmi-2-0-everything-you-need-to-know-1180242

Will I need to buy new HDMI 2.0 cables?

That depends. You can use your existing HDMI cables with new HDMI 2.0 connections as the connectors themselves haven’t changed. While there’s no such thing as an HDMI 2.0 cable per se, displaying 4K at 50/60Hz will require a High Speed/Category 2 HDMI cable. You can pick one up for a few pounds/dollars online. Don’t spend any more.

The Monster cable listed is a Category 2. It wasn’t rated higher when it was sold because a higher rating did not exist at that point. It is NOT the limiting factor. If I had a new GPU I could prove that in an instant.