Wow, so nothing of substance happened to that family after causing a foreign relations incident that ended communications between two countries?
I get the feeling the implication is that the Roundheart family (Logos the farther, Glint the son and Camilla the second wife) were all in the dark when it came to Olivia's heritage. The first few chapters make Olivia out to be the daughter of an influential trading company, rather than royalty or nobility, prior to the reveal. Otherwise there would be no way they would even think to openly slight the second princess of the most powerful kingdom in the world in the way that they did.
Having said that, I don't understand what the author has in mind writing the plot like that. It begs the question, who in Hyme knew about Olivia? Did the royal family, who probably set up the trade agreement with Ishtalica know about Olivia? If this trading relationship was so important to Hyme and Ishtalica, why would either country decide that marrying a princess off to a random lesser noble was at all a correct thing to do. Maybe Olivia was there to spy on Hyme in someway to make sure that Hyme kept up on their end of the deal. That would make sense, until you remember that the trade between was two countries was halted on account of Olivia's (and Ain's) poor treatment rather than any level of country wide corruption.
I think the initial set up is honestly either poorly thought out, or maybe poorly adapted from the light novel (which I haven't read so I can't make judgement).
EDIT: I misremembered it seems Logas, is a general of Hyme, not a lesser noble. Also reading ahead it seems the Royal family at least was aware somewhat.