Sadly typical to see people make these accusations without even doing a Google search. Answers to least two of these are in the FAQ:

https://faq.soylent.com/hc/en-us/articles/203962069-Vitamin-...

https://faq.soylent.com/hc/en-us/articles/204547005-Magnesiu...

I'm not enough of a nutritionist to say whether that's really sufficient, but they do consult with nutritionists, so it seems likely they've at least thought about all this stuff. Proving there's something wrong with Soylent is going to take more research than anyone's likely to casually do for an Internet discussion.