They're trying to remove the bias present in the training data. The data on the internet vastly over-represents content from wealthy countries who were connected to the internet earlier, and the AI will learn this biased distribution to the point where if you ask it to generate a picture of a "person", that person may be White 100% of the time. Attempts by Google to instead model the true underlying population distribution is probably done in a very hacky way, such as putting guidelines in the system prompt, which then leads to outcomes (which are cherry-picked and put on social media as culture war outrage bait) like what you're talking about where a "Swedish woman" occasionally doesn't show up as White.