Some textures provided in this resource pack are from the Minecraft Java Edition client jar. GeyserMC does not claim ownership of these textures - these are all created and owned by Mojang.
The Minecraft EULA (https://account.mojang.com/documents/minecraft_eula) cites:
If you've bought the Game, you may play around with it and modify it by adding modifications, tools, or plugins, which we will refer to collectively as "Mods." By "Mods," we mean something original that you or someone else created that doesn't contain a substantial part of our copyrightable code or content. When you combine your Mod with the Minecraft software, we will call that combination a "Modded Version" of the Game. We have the final say on what constitutes a Mod and what doesn't. You may not distribute any Modded Versions of our Game or software, and we’d appreciate it if you didn’t use Mods for griefing. Basically, Mods are okay to distribute; hacked versions or Modded Versions of the Game client or server software are not okay to distribute.
Any textures included in this resource pack are contingent on the "substantial" part. As only a fraction of the content here revolves around Mojang property, we consider it not "substantial".