You’re both right of course about too much noise on github, but in the end, darktable is an open source project and that implies a certain amount of freedom for users to express their opinions. There are no technical restrictions on who can raise issues or comment on the github project but I would hope people are able to show restraint and only comment where they think they can positively contribute to the discussion.
There’s no problem with people discussing upcoming changes on these forums (and people often do so) but I wouldn’t necessarily expect the developers to initiate those discussions or participate in them. I expect some of the developers don’t even have a pixls account.