That is correct Paul.
The G'MIC plug-in for Krita has been done by one Krita developer who is not active anymore (at least it seems so), so the plug-in is stuck to use an older version of G'MIC.
*But*, we are currently trying to develop a kind of 'universal' plug-in that is intended to run the same in Gimp and Krita in the future.
That is still work in progress of course, so we are not even sure the goal will be reached

Below is the video of this upcoming plug-in, partially working with GIMP :