The article doesn't make sense, and I honestly struggle to take anything from Emrathich seriously. Truls didn't play the Olympic because of injury and maybe they wanted Kallberg to have a chance since he had displayed better form and Karlsson may not have liked it. But what I will say is that if Sweden wants its best chance at a team medal, Karlsson is their only viable lefty and his best partner is Falck (nee Karlsson). Truls is the best singles player. And then it comes down to who is playing better between Falck and Karlsson for the other singles spot. I think they have tried Truls and Kallberg/Bergstron in mixed doubles and maybe Karlsson and Kallberg /Bergstrom for mixed doubles.
Of course all this is speculation but this is how I see it. Karlsson and Falck have proved themselves enough that they clearly give Sweden a doubles point against just about every team in the world, and they are both very strong in Singles with Truls. This is a chance at an Olympic medal against a lot of Asian teams - unless they just want to compete for 5th place, no other option is serious.
It was basically a translation with a clickbait title from an article in swedish reporting the same thing, anyway Karlsson performance in that period was quite bad so could've kinda made sense. For mixed doubles I certainly don't expect Bergstrom, with Truls they had a quite poor performance in the europeans, simply because chopper + attacker pair usually doesn't work well, Karlsson instead could be a good pick since there are no left-handed female players, maybe Karlsson + Stina Kallberg