I am generally not in favour of hammering down Karma's "disruptor" qualities. Those weren't part of her original design and they didn't make her any better, when they were slapped onto her for no apparant reason. It just watered her identity down. Karma used to and should be a battlemage/enchanter. While I do agree that the 1.25s bonus root should be removed from her kit, replacing it with the "grounded" effect doesn't seem to be a good idea.
Why?
Because with Karma's slow and ms buff she can very much guarantee the root already. Just slapping the "grounded" debuff on it only removes counterplay without adding any meaningful depth, synergy or needed power to her kit.
Reintroducing the bonus damage and replacing her awkward missing%healing with a flat healing that scales with low hp makes more sense. Both for her decision making and buildpaths.