Hmm... eh it probably has been done before. The platies would probably make a nice fishy treat as opposed to bugs, worms, and etc.. You are the first person who asked if platies could be food for snakes here lol. It's definitely okay, I'd say, if they are gut loaded nicely and not sick or anything..
20 gallon - Sulawesi Golden rabbit snails/Japanese Trapdoor snails/RCS/Marbled crayfish tank
55 gallon - Rainbowfish Dutch scape low-tech planted tank
250 gallon - Community Tiger Oscar/Red hook silver dollar/Silver dollars/PB Jack Dempsey/Clown loaches/Tinfoil barb/Roseline sharks/Bala shark Monster fish tank