As to grappling and knifework, I think it still should be addressed. One doesn't need to grapple like one is entering the UFC, but one does need to learn to grapple enough to prevent getting dumped on the ground in a less dominant position in a fight, or to prevent from being overtaken on the ground if you end up there.
Where grappling fits in with knife work, and how it should be trained if one is preparing for what may happened in a fight, is the scenario where someone try's to pull a knife, or pick something up that resembles a knife, while on the ground, or while in the standing grappling range. You could also consider if someone dumps you on the ground, or you trip, and his friend gets involved, and he is armed with something sharp. You have one guy grappling up on you, and another that is now armed with a sharp tool; not a good situation to be in, but better to work out these problems as much as possible in training rather then to be stuck with whatever happenes if this does occur in a fight. There are live exercises and scenario sparring type drills that can address these situation in training. And, these types of situations need to be addressed, or one is missing a major part of what may happened in reality. Remember: we don't rise to our expectations, we fall to our level of training and preperation.
As to the idea of attempting to grapple with a knife wielding assailent as you would if you were grappling on the mat in a match - this is something I would not recommend. The variables are entirely different in reality then on the mat, making this approach a very bad tactic that can get you killed. If all one focuses on is his hammer, then every problem begins to look like a nail. There are a lot of other tools in the toolbox that should be used against a knife wielding assailent, starting with the most noble tactic of running to safety.
Lastly, it is still important to grapple... period. "Anti-grappling" starts with learning how to grapple. You can't learn to deal with a grappling situation without getting on the mat and understanding how to utilize your body in the clinch or on the ground. The solutions to the problems of grappling in a fight must to start with grappling in practice.
Just my extended thoughts on the subject. Take it for what it is worth to you...
Yours,
Paul