Hi, Kombowz!
It's not that simple, I'm afraid. JSON is just a format for a data, but the actual data and data structure that is stored varies wildly between software/tools/etc. In Unity version of CC2D, the JSON only saves what parts are used for said character, so that you can load it again anytime with CC2D or save any character data during runtime. I imagine the Spine JSON would contain animation data and a bunch of other things that are specific to Spine and its runtime implementation.