Required changes identified in the review on T327570:
* [x] Update messages about revealing your IP address in the tools
** {T335532}
** https://gerrit.wikimedia.org/r/c/mediawiki/extensions/DiscussionTools/+/912999
* [ ] Correct signature in the preview when a temp user would be created
* [ ] New empty state messages are needed for temp user talk pages
* [ ] ~~Temp users probably shouldn't be listed in the mention dropdown, if they can't receive notifications~~
* [ ] Temp users shouldn't see a link to change their preferences
* [ ] New topic tool doesn't seem to work for temp users, investigate
* [ ] Topic subscriptions should be consistently unavailable for temp users
* [x] {T332437}
** https://gerrit.wikimedia.org/r/c/schemas/event/secondary/+/907960
** https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikimediaEvents/+/907964
** https://gerrit.wikimedia.org/r/c/mediawiki/extensions/DiscussionTools/+/907969
We should also probably make these changes suggested in Tim's initial review for VisualEditor on T307056:
* [ ] Redirect through login.wikimedia.org in order to acquire CentralAuth cookies.
* [ ] After save, a notice should be shown, as in core (mockup F34933175).