Fighters might make the most sense if it is a procurement winner announcement since which ever way we go is, in my opinion, still going to involve a substantial number of F-35s, and all f-35 or mixed fleet there will be much more controversy and parsing of the various moving parts than there will be with the subs.
That being said, at an international summit I'd be looking for something much more high level in terms of defence policy, budgets, future structure/plans etc. Maybe related to the bank or new commitments to the front lines in the Baltic?