Fresh unlisted topics get emailed to 'watch first post'

I think this is a bug related to behaviour that others have noted…
Situation: Have global notifications category that only admin/management can post in, set every user to watch first post to ensure emails go out. If I create a topic toggled as unlisted (from topic create, before it’s ever made public), it still sends email notifications. The goal is to have the team wiki the announcement before it’s published per se, but sending it out a rough draft is a bit annoying.

Alternatively we can have an editors category, then have someone move the completed topic to announce, but it seems like extra work for what should be invisible. (If intentional, then it seems to defeat the purpose of having ‘toggle unlisted’ in the topic create menu.

My searches:
How unlisted should work

Someone else noting that mailing list mode sends unlisted

Noting that ‘send me all’ gets further emails after a topic is unlisted.