I'm not sure it's intrinsically bad news for the diet (but I won't dispute that it's a challenge for how it's usually followed). I haven't met one, but I've at least heard that there are vegans following ketosis-inducing diets.
For example, I just ran 4 marathons in 5 weeks in my late 40s eating mostly WFPB. That's good-enough health for me.
From my normal keto diet it basically meant I stopped eating eggs/bacon and meat. Vegetarian was easier than vegan because I could still eat eggs.
Ketosis definitely can be achieved with “whole food diets” and “whole food plant based diets”