I always say start small to create gravity. For product communities, I generally recommend:
announcements or from-<company> . Make sure only admins can post in this channel (usually it’s general renamed)
product-feedback. When active enough add a help channel
say-hi or intros. Probably the most important channel as it helps people recognize they are not alone in the space.
Everything else after that is simply taste and opinion.
My 🪙🪙