That doesn't mean much when the discord TOS forbids use of anything but the official client to connect to their services. They seem to turn a blind eye to the various unofficial clients mostly, but also do occasionally ban a subset of their users occasionally despite no other TOS violations.
How can I possibly trust the Discord client is actually using that library and not a modified version that calls home? The whole point of using open source is being able to see the entire code of the program, and compile it yourself