Their many other forays into new markets.. We may eventually get a more international catalogue but initially it will be mostly local
They'll offer "fulfilled by Amazon"/"fulfilled by <company name>", that is 100% for sure.
What you should be asking is, if something is "shipped and sold" by Amazon whether they'll use local suppliers at all.
In that case the evidence and data is clear, they may initially and as soon as it makes financial sense they won't.
There are plenty of cases where Amazon simply skips the local supplier.
If the distribution company/manufacturer doesn't want to play ball, Amazon stops selling their product, globally, and then they lose so much money they simply cave (plenty of articles about companies crying unfair about this)
Very few companies have had the market domination to avoid this (Apple and Google being examples that are no longer offered by Amazon).
But yeah if a local supplier is making fat stacks and Amazon can get a better deal by going direct, don't think they won't do that.
They absolutely will and do undercut where it makes sense.
They even go directly to manufacturers with Amazon branded products if they can offer the same product with the Amazon name for cheaper (or make a clone for cheaper)
They only care about customers, that is their core principle (customer obsession).
They give 0 f#cks for businesses, because getting things cheaper for customers and controlling the chain means you can do better by your customers.
Frankly I fully support that model, there are too many places in the world where there are supplier like Esquire that screw over customers and they get away with it because no-one can challenge them financially.