JetBrains’ AI code suggestions were only trained on code where authors gave explicit permission for it, but that’s the only one I know from the top of my head. Most chat-oriented LLMs (ChatGPT, Claude, Gemini…) were almost certainly trained using corporate piracy.
In my opinion GitHub is seriously good software, but it is awkward when FOSS software is developed on it instead of on Codeberg, Gitea or another FOSS platform.
Discord is actually a security risk, it walls information off the outside world (compared to a forum or IRC server) and incredibly difficult to find information in even when you’re in the server (as opposed to documentation or a forum)
Matrix has 2/3 of these issues, so it being FOSS aside I very much would hate it when development discussion and software documentation is done through Matrix, as well.