our team has already deployed Jira DC. We were in contact with Atlassian and utilized what was recommended including support channel.
It was recommended to have Thready in place in DC setup as well. We did highlight during our discussions that it is weird that it does not have tag of "supported" and relevant up to date label suggesting it was tested in DC. Prior DC, we had Thready in all our instances. I can confirm that we have not faced any issue with this plugin to date.