If you would like to use the Spine Runtimes to play the outsourced animations in your game, then yes, you need a Spine license to distribute the Spine Runtimes. Note you can distribute any number of games or apps containing the Spine Runtimes with a single Spine license. Spine Essential is sufficient to use the Spine runtimes in your apps (unless you make more than $500,000 USD in one year, then you need Spine Enterprise).
If the outsourced animation is exported as images or video, then you don't need the Spine Runtimes and therefore don't need a Spine license at all.
If you would like to edit the animations in Spine, you would also need a Spine license. If the animations use Spine Professional features, then you'd need Spine Professional (or Spine Enterprise).
