Chipotle already doesn't manufacture the vast majority of their ingredients. Their business consists of delivering supplier-originated ingredients to a standardized storefront in your city and consistently assembling them into a quality burrito, with small amounts of prep work for things which can't be consistently sourced locally and in-store cooking for things which must be prepared fresh. I don't know where people get this idea that packaging and assembly are trivial tasks you can't build a business around.
You make a good point. Chipotle sources locally, cooks things in-store and sells fresh things, none of which are things that any Taco Bell does, so it would really be funny for them to announce that they are switching to being a place that puts Chipotle wrappers on Taco Bell food rather than what they have an established reputation for doing.
US Foods and Sysco supply most of the restaurants, literally every single restaurant food you see is just a minimum wage wrapper around US Foods/Sysco produce
