Some good news on this one. Our changes have been merged into this pull request: Update tests by StorytellerCZ · Pull Request #173 · Meteor-Community-Packages/meteor-publish-composite · GitHub. It is awaiting review and hopefully will be published soon.
tmeasday:publish-counts
A package often shunned because of performance issues with large collections (but that is just simply misuse!), otherwise very helpful in a multitude of use cases. We just submitted a pretty big pull request here: Meteor 3.0 compatibility by manueltimita · Pull Request #99 · meteor/publish-counts · GitHub. The repo still looks maintained, so hopefully it will be merged soon.
deanius:promise
Another package that seems to be still maintained (@storyteller’s pull request from 2 months ago got merged). We also submitted a pull request there, for compatibility with Meteor 3.0: Compatible with Meteor 3.0 by manueltimita · Pull Request #35 · deanrad/meteor-promise · GitHub