Thank you for sharing this article! This prevented me from working on projects and software.
Not only FOSS projects should refrain from using Discord. Community-driven projects like Skywind are barring themselves from helping hands, they desperately need, by using proprietary, privacy-threatening software as their way of communication.
You're asking them to set up and maintain another platform for you to ... Checks notes... use their FOSS project? Not contribute to development, just...use? That does not seem worth their time. Certainly sounds demanding to step into a project and tell them to do things differently otherwise you won't honour them with your presence