Yes, because like I said: marketing. "Protein Shakes" are a bigger/more popular niche than "Meal Replacements", so naturally a lot of products are gonna double dip and try to claim belonging to both categories. But that's irrelevant because what matters is the actual nutritional​ composition of these products.

Soylent has 20g of protein per serving, and most of the products listed above are also in that 15-30g of protein range and share most of the same micronutrients, so functionally they're about equivalent. The only real differences between all these products are marketing, price, taste, "recommended" serving sizes, and small tweaks in nutrient ratios. Other than that, they're all pretty interchangeable.

The serving size is the whole freakin' point. If you were to consume 1 bag of the Soylent powder, or 5 bottles of the pre-mixed drink, you would have exactly 100% of your RDA for most macros and some micros (+/- some modest amount) for a 2000cal diet.

This breaks down easily into per-meal replacements especially for the powder. Half a bag is half a day's needs, and so on.

That is literally the whole reason Soylent exists. As far as I know, it's the only product that works that way at that price point.