As Vanguard retail funds are now closed to new investors, there is a risk that over time these funds may no longer be economically viable to operate and could result in increased fees or termination of the funds. This proposal gives you the opportunity to participate in a one-time transaction to transition to our larger wholesale funds without triggering a capital gain.
I can see the logic in letting their market-traded holdings be managed by someone else. JPM and ANZ would already have the expertise and infrastructure in place to run a brokerage and commercial bank account respectively. Not to mention having the required regulatory compliance. Probably cheaper for Vanguard than spinning up their own teams. Also probably cuts costs by not having to administer two separate businesses which run parallel.