I think this makes sense, but at the same time I think the list in the task description illustrates there is no real forum for discussing MediaWiki security issues outside of well, Phabricator tasks, which doesn't really scale for broader things and IMO tends to get lost in all the other bugmail (might be just me!).

We used to have a mediawiki-security discussion mailing list that csteipp briefly used, maybe we can consider bringing it back?

No opinion. It is true that the channel does not have much activity, especially since _security seems to be used one. However if the -security one gets closed, I'd like to request that I be allowed into _security one so I can keep reporting security issues or incidents if possible. Thanks.

Ok, sounds like we have some mild consensus so far, at least. I'm fine leaving this open for another week or so and will then likely decom the channel. @Legoktm - I'm fine setting up a new security discussion list. I imagine that'd also be low-traffic but it's also low-cost to establish.

In T333722#8748884, @MarcoAurelio wrote:

No opinion. It is true that the channel does not have much activity, especially since _security seems to be used one. However if the -security one gets closed, I'd like to request that I be allowed into _security one so I can keep reporting security issues or incidents if possible. Thanks.

I agree (also see what i mentioned in -security itself). We've some security team members in the internal steward coordination channel (do we want to add others?), so perhaps this is not an issue for stewards, but maybe similar "where to coordinate with secteam" questions exist for other secteam partners?