Well, facilitators and enablers will be in demand regardless of what methodology you subscribe to. For the last 8 years I've been a product manager (& director). This is one of those jobs that if you do a mediocre job, at best you'll be a nuisance, at worst an impedance. If you do a stellar job, your team's productivity will skyrocket and so will the returns on the investment.

PMs, like many other enablers/facilitators, are there to weed-out noise and make sure the team is always in the know on the relevant context and insights. When things go badly, strong PMs provide cover for the engineers to work through the storm and continuously synthesize all forms of feedback to ensure engineers have proper situational awareness and facts to make sound decisions, but not thrash in response to whatever strife might be out there.

There are other "managerial" type professions that have a place and make things better. All good managers know how to resolve conflict and make sure the team knows about any land mines, but also knows when to get out of the way and let people work. Individual development is also the job of the manager.