I'm wondering how much success they would have there. I think they may well have missed their window of opportunity. There are more than 30 different makers in the EU now (13 in the Netherlands alone!). There is a wide range of prices and of choices of ingredients. Most are powders but two (Feed and Mana) offer RTD products as well, and I would be surprised if there are not more RTDs coming this year. So Soylent would be entering a very crowded market full of already successful "soylent" products.
There would be a small number of people who are aware of meal replacements and who know this is "the original" and so might try it out of curiosity. But it seems unlikely to me that being "the original" is enough to make people switch permanently from Huel, Joylent, Queal or Mana to Soylent. There would have to be either a distinct price advantage, or a clear and easy to communicate nutritional advantage, or a clearly better flavor.
Price? I doubt that Soylent could seriously underprice Joylent even if they manufactured in the Netherlands.
Nutrition? Everybody delivers about the same mix of macros and a complete set of micros. Everybody is "organic" and "gluten free" already. Several can say "non-GMO" or "no Soy" which gives them an edge over Soylent. Even if those words mean nothing, as I think they do, they are significant to some consumers.
Flavor? Most offer chocolate and vanilla already. Huel ships flavor packs to mix with its powder. Joylent says "I'll see your Nectar and raise you a Mango and a Banana."
So frankly I don't think Rosa Foods should bother trying to crack the EU. They'd be fighting for customers in a crowded field with no real product differentiation and no price advantage. They would probably do better trying to move into Japan, South Korea, or India, where there aren't a lot of competitors and being a real American product carries some emotional value. If they could find a trustworthy local manufacturing partner in China, that would be an immense market which they could have all to themselves.