This is what makes me a bit skeptical of the hire.
It's fairly unprecedented for an agent to get this job (I know somebody mentioned Burke but still....pretty rare) and it just so happens to be McDavid's agent when McDavid is a few years from free agency. The change is nice as long as Nicholson is out but I question the motive behind this hire, has a nepotistic (if this is a word) feel to it.
Kent Hughes was hired as GM after years as a player agent, IIRC.
This is actually less impactful in terms of actual player negotiations, signings, etc, and moreso on how the organization is run as a whole (e.g. how much stock is put into analytics, governing who fills roles when they become open, and just generally steering hockey ops in a forward looking manner).
I'm a fan of the hire. Really hard to make the successor any less competent than the incumbent, IMO.
One more thing: Jackson is someone who's worked as an executive at multiple organizations (AGM & Dir of Hockey Ops with Leafs, Partner at Orr Hockey Group, EVP at Wasserman). He has qualifications. It also helps that he's McDavid's agent, of course.