Deadline report is the "High Command of the Federation" (Federation President? Starfleet Commander in Chief?).
There are no details of what role this character will have in the story. Does this imply we'll get scenes in the President's office in Paris? Is the character Human? How come another character is being added only now? Who knows! Reshoots aren't exactly uncommon for big films these days, and if adding a new character implies something lacking before, well, hopefully said new character fills that gap!
Aghdashloo should feel at home as a sci-fi politician, having recently starred as a UN official in Syfy's series The Expanse (pictured). Her long acting career has seen appearances in many films, TV series, and voice work for animation and video games, including diverse roles in comedy, drama, action, and sci-fi, such as 24, Grimm, and X-Men: The Last Stand.
Star Trek Beyond is still set for release on the 22nd of July in the US. Hopefully we'll get a second trailer, or something else promotion wise soon, as it's been awfully quiet since the first trailer was released in December. There is also a conspicuous lack of merchandise news, with just Eaglemoss currently known to have plans for model ships, and the suggestion there will be no novelization or tie-in comic series.
There is some other news though, the movie website now lists the international release dates for the film. If you want to see it first, then you'll need to head to Thailand, who are getting it on the 19th of July! A lot of countires will be getting it a day or two ahead of the US too (though sadly for me, not the UK this time, which matches the 22nd release date). There are a few countries who have to wait until August, and unlucky Argentina won't see it until the 1st of September! I expect the page will see additions and adjustments over time, but this is the list for now:
To keep track of all the latest information on the film, visit my Star Trek Beyond guide page.