Ditto, US airlines already have very extensive fifth freedom rights within and beyond the EU. With the exception of FedEx and UPS, they don't use them.
Rule number one in this business is don't venture outside your core market unless you want to risk getting badly burned. Only exception is if you have an extremely strong brand - like Virgin, Easy ... or FedEx and UPS.
What *can* be done under the agreement and what *will* be done are two very different things.