Keto (and a lack of surprise) came to my mind when I read the title too, but your point is important for anyone learning about the ketogenic diet - keto is a binary state, you're either in it or you're not (and you can do a urine test at home to tell).

There are still benefits to cutting carbs without going full keto, but not because you'll be '50% keto' or anything, just because there are other health improvements from lowering carbohydrate intake other than possible ketosis.