Brian-Smith I don't think anyone was saying to give away Project, or force payment for Planner. It becomes a licensing issue. Planner would be the 'free' tier of functionality, Project is the professional tier of functionality, but they're the same system behind the scenes. Pretty much all of MS's licensing works in this way, after all. MS365 Business (Basic vs. Standard vs. Premium) is mostly differentiated by what you can access and edit, not entirely different but related products. Heck, even Project has Online Essentials, and then Plans 1, 3, and 5 offering differing capabilities.
Keep the same integrated back end that flows the data seamlessly between Planner and Project such that our teams can continue to use Planner for their day to day but management can use Project to coordinate and set roadmaps. We're *this close* to that as it is... the final gap is what is maddening, because it is so bleeding obviously needed.
Senior management uses Project to create large scale projects with complex dependencies and cross-team coordination. Project leads use their view of the same data within Project Plan 1 or Planner to coordinate their teams. Team leads use Planner (same data) to direct collaboration among individuals. Individuals see their actions on their Tasks (SAME DATA) for day to day checklists. If the master Project is updated, the data flows down the entire chain. If an employee checks off an item, that status flows *up* the entire chain and is reflected on the status of the master project as needed. The UI becomes a matter of expression of the data, and editing capabilities based on the access rights provided by the tool license and/or role in the organization.
I really do hope you're moving towards this model, because right now Project is a hard sell within our org, but this would make it a clear path.