I suspect it is part of the deal with Australia which, I'm confident, is making a significant financial contribution to having a Moderna research and manufacturing facility in that country. I suspect Australia is getting more than priority in getting new products manufactured there in return. First in the field on x number of product candidates may be one of them. If so, it costs little to nothing.
Yeah, Moderna is "wired" to the local medical community. There is a reason why the Boston area doesn't already have multiple sites recruiting but I don't know what it is.
Watch to see if Canada is next in exchange for their support of the facility being built in that country. I have not idea whether "little things" are exchanged in deals like these.