I don't think that's all that strong. It's reasonably well-known that processes such as heating, drying, canning, and so on tend to reduce the nutritional value of fruits and vegetables - such as vitamin B and C, sulfurophane in broccoli, antioxidants in blueberries, etc. A quick google should reveal a ton of studies. So it might not be surprising that extracts have these kinds of issues as well.

I think OP is probably right that these meat substitutes are less healthy than eating veg in its raw form, but perhaps the question should be how they stack up nutritionally against the red meat they're replacing.