Not a shrimp expert but I know RSC (in general Neocaridina) and Amano shrimps will eat diatoms. Otocinclus fish and several species of suckermouth fish also love it. Snails will feast on it. If your tanks cycles fine and do your scheduled maintenance you won't see diatoms soon enough though.
I will let the usual experts answer the question thoroughly.
All vegitarian and omnivorous organisme from high to low and available in our hobby feed on diatoms and also green algae. It's a major but not the main source in the food chain in aqautic invironments. Thus what ever eats from it, is never the remidy but only a small part of the solution as cleanup crew. And all shrimps are omnivorous..