Assets you create with Spine (eg Spine project files, skeleton and animation data, images, video) are your IP, they are not encumbered by Spine's licensing in any way, and you can do whatever you like with them.
Licensing Spine allows using the Spine editor (section 1.1) and allows use of the Spine Runtimes in your applications (section 2). If the company doesn't need to use the Spine Runtimes then they likely still needs to license Spine to use the Spine editor and would need Spine Enterprise if they exceed the annual revenue threshold.
