Hi Greg, welcome to the community 
The idea is Monzo users will be able to purchase all services you’ve listed in Monzo’s marketplace.
That means that rather than having to sign up for whichever bundle of services your bank’s decided are best for you (&/or most profitable for them), you’ll have a choice of providers for each service. So if you need cover for action sports in your travel insurance, for example, you won’t have to worry about whether that’s included & the providers will be competing, which should drive down prices.
By creating the marketplace, Monzo will (hopefully) make it easier for users to access these services & certainly make them easier to manage - as they’ll all be linked to your Monzo account. They’ll also be able to do clever things like spot when you might need travel insurance but forgot to buy it, before you left the country or remind you to cancel your breakdown cover, if you don’t renew your vehicle tax.
How does that sound?