@Konstantina Antoniadou I'm not sure I know what you mean by "auto-created plans" when you refer to Yammer Resources. Are you referring to the Planner board that gets provisioned along with a newly created suite-connected Yammer group?
@Konstantina Antoniadou That's an interesting observation. The lack of comments is related to the fact that Office 365 Groups connected to Yammer do not have the Outlook distribution list feature enabled. The comments in Planner leverage that distribution list.
Seems like a feature gap that the Planner team could address.