It might be my non-nativeness but a meal replacement doesn't sound like a food replacement to me. At least, not if you don't want to.
The whole concept is experimental and everyone knows that. Doesn't mean they should be allowed to sell a product known to make people ill, but if you replace 100% of your food you shouldn't be surprised if it turns out they forgot an ingredient or put a little too much in for your specific lifestyle.
Too late if they have already lodged that in everyone's mind - they should have gotten a new brand if the brand proposition was going to be radically different.
The whole concept is experimental and everyone knows that. Doesn't mean they should be allowed to sell a product known to make people ill, but if you replace 100% of your food you shouldn't be surprised if it turns out they forgot an ingredient or put a little too much in for your specific lifestyle.