It doesn't make sense for an open-source group making open-source projects and strongly promoting open-source to use such a tool for group chat. There are plenty of open-source alternatives or alternatives with no such negative association.
edit: it looks even worse knowing that they have their own chat project: https://twake-chat.com that is powered by the Matrix protocol
edit: it looks even worse knowing that they have their own chat project: https://twake-chat.com that is powered by the Matrix protocol