Southwest Rapid Rewards - "New" Recycling Program - Why not Plastic Cups?

On my flight tonight the FA announced WN has started a "new" recycling program today and they had bags specifically for recyclables, which they said were aluminum cans, plastic bottles, newspaper, and magazines.

Question for Brian (or any WN employee with the answer!): Why not the plastic cups?

On my flight tonight the FA announced WN has started a "new" recycling program today and they had bags specifically for recyclables, which they said were aluminum cans, plastic bottles, newspaper, and magazines.

Question for Brian (or any WN employee with the answer!): Why not the plastic cups?

They have been gathering cans separate from trash for the past few months on the BDL-LAS-BDL flights.

I could have sworn that a WN employee reported in the past that airport trash was always separated after the fact-that service providers bid on the opportunity then recover cans etc. (always seemed like a pretty gross job description, never know when you'll find a diaper or air sickness bag)

I'd imagine because often the cups have liquid in them with ice or the beverage and thus would "contaminate" the other recycleables. Otherwise, it could be they aren't the right kind of plastic - many recyclers only take Type 1 and Type 2 plastic.