I work on a project (funded by a US grant) that is organized with a PI(principal investigator) team consisting of ~5 people and a development team under them with ~8 developers. One of the developers is the Lead Developer and communicates with the PI team to give weekly updates and trickles the information down to us developers. The developers meet once a week to discuss progress, blockers, etc. The project spans multiple universities, and my boss is on the PI team. One issue that we're having is lack of organization on the GitHub repositories. For example, we have milestones but no one will attach their issues to it.
When meeting with my boss (a PI) he asked to update the milestones and come up with release dates. Traditionally this has been done by the lead developer. I would feel out of line/place asking everybody on the team to update their issues and put them in the correct milestones. To me, this is bypassing the chain of command (PI->lead->devs) to (PI->dev).
What is the best way to satisfy my boss's requests without bypassing the lead developer and making requests to people above my pay grade?