Good news tanks, Healer Threat has now been nerfed further in MoP Remix.
In the latest hotfixes, Healer Threat Reduction has been changed to -95 (was -75). This means that characters in MoP Remix generate 95% less threat from healer (was 75%). Threat was always very unreliable in MoP Remix due to scaling, with tanks constantly losing threat to low levels easily.
Hopefully this helps Healers not pulling aggro from just healing.