I have personally tested all of the Pokemon, excluding Pokemon that were introduced in Gen 7, to see if they could eat Pokepuffs, and the only ones that couldn't were Metapod, Kakuna, Pineco, Silcoon, Cascoon, Shedinja. I would assume that the same applies to Poke Beans, but I'm not sure.
If I can somehow get my hands on all of the new Pokemon and forms introduced in Gen 7 and the Pokemon that cannot eat Pokepuffs, I would gladly test to see if they can eat Poke Beans, but I refuse to test to see if ALL of the Pokemon can eat a bean or not.
Typing this comment made me realize that I spent a large amount of time last year seeing if 721 imaginary creatures could eat a tiny little cupcake.