As important limitations on evaluating the authoritativeness (none) of my answer, it needs to be pointed out that I’m not involved with the Surge or Metabolic Drive formulation efforts nor is that an area of my expertise.
And I’ve never had the above topic brought up to me from anyone who is involved in that. So, please appropriately discount my reply as definitely not being inside information.
First, I don’t think sugar alcohols would be involved.
Second, while there are some RTD protein products that are nice to drink and seem at least reasonably decent products, for example the Labrada RTD protein drinks, it seems to me that the formulation is always different than what the same company will choose to use for a powder product.
Is the formulation compromised to yield a good RTD? I’ve tended to guess so, though I don’t know for a fact that there could be cases of “different but equally good.”
Though using the Labrada products again as an example, I do think their Lean Body powders seem better nutrition than the RTD (though there’s an almost absurd problem with excess iron being added: a truly bad idea.)
That is what I would think the technical issue might be: whether Surge and Metabolic Drive could be equally good as RTD’s. Possibly that is the case, but possibly it is not. If it isn’t the case, that very well could be the explanation why they don’t exist.