Not necessarily the senior people. In my organization, we convene a "Safety of Flight" briefing for all but the "low risk" tests. A senior manager plus the Chief FTE & Pilot must also be there but we also invite everyone involved in the actual test requirement which could be even a student engineer.
The FTE conducting the test has a list of risks & mitigations for each of the test points but they can be questioned by anyone at the briefing. More than once, it's been the lowest in seniority that's brought up something that's been overlooked especially where it's a specialist test such as Autopilot or other Avionics system.