Awesome idea, though I see some difficulties:
But such a group could get quite big and many providers limit how many recipients a message can have. (most providers are between 20-50 I guess) this number is also the max group member count in normal group, you can not send messages nor leave a group that is bigger than your provider allows.
One option would be mailing list support, that’s on the roadmap but not implemented yet.
Another option is to use a bot to relay message, @adbenitez’s simple bot can do this in a feature called mega groups, but until BOT - Impersonate / Alias names is implemented in delta chat it doesn’t look/feel like a real group.
Also we are against centralization, so one official, public delta-chat discussion group is nothing we want to moderate/host/take care of.
We have a testing group though, you can ask @compl4xx to add you to that.
Also feel free to start such a community group and advertise it here.