Aussie mRNA manufacturer 2b DECIDED this week, page-27

Yes, they have pre-ordered alot of vaccines, but that isnt to say as part of those agreements there were clauses that relate to a certain percentage being manufactured here by a local entity.
There is also scope for vaccines manufactured here to be exported. It's potentially larger than just the domestic market.
One of the main reasons why novavax has yet to approved by the TGA has to do with concerns around manufacturing consistency and standards. What better way to address those concerns by having it manufactured here.