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Facebook Page - primary place to see new events
WhatsApp Community - only used for announcements, 100% sure way to always be notified
Facebook Group - the original place, sometimes other events are posted there
None of these have any sort of online chat or discussion. I find those intrusive as they often turn spammy. These channels respect your attention and exist only to inform about the events. If you want to talk, come to real life meeting and talk :), that's sole reason why these events exist, to connect people. ~ Jan