I'm glad that William and Harry remained friends with their ex-girlfriends. Civility is always to be commended. I still think it's tacky to invite exes to your wedding, no matter how well you get on with them. Obviously, if you have a child or children with them, that's different. Also, why would Sofia think Carl Philip's ex-girlfriend was a threat? Did she think Emma was going to sneak into their house and jump out of the closet with a butcher knife? Lounge seductively on the bed wearing lingerie? Put rat poison in the champagne? That's soap opera nonsense. The only time an ex-partner is a threat to the new partner is when they're violent, and that violence is why the relationship ended.
Can't say I'm surprised, really. I don't live in the UK, so I don't have an ear to the door, as the expression goes. Are the York princesses all that interesting or popular to people? William and Harry have the benefit of being sons of the future king, to say nothing of the attachment people continue to have to their late mother, so that explains in part, their popularity, especially here in the US. Beatrice and Eugenie, as lovely as they are, don't have that.