The Federal Government's thought process seems to have been:
Neither Via Rail nor our civil service has the expertise to plan, design, build. and operate a high frequency intercity railway so we'll need to bring in expertise from places that already have these skills.
We need to provide an incentive to attract this expertise, so we'll offer an opportunity to operate and maintain the railway over a long enough term that proponents can both make a profit and pay for the planning, design and construction of any new assets needed.
By creating a Via Rail branded crown corporation and having it contract with the new rail company we can continue to brand the new services as Via Rail services.
To be truly useful, there needs to be seamless ticketing between regular Via Rail and HFR Via Rail so a I can make a single booking for a journey from London, ON to Montreal, QC.
Hopefully the contractual arrangements will be more like the Contract for Service arrangement that now exists between the UK government and their Train Operating Companies than the previous Franchise Agreements that transferred more marketing, branding, and sales to the franchisee.