Oatmeal doesn’t cause it like so many other carbs.
It’s a whole grain and that regulates entry into the bloodstream.
It depends on what kind of oats are used, and the article in question did not mention which type of oats were used. I would agree a little bit more with you if it was steel cut oats, as opposed to the rolled oats or “fast“ oats that people typically consume (at least in the U.S.). There was also no mention made at all of whether or not anything was added to the oats. I’m assuming there was no sugar or other sweetener added, but if there were some fats added such as butter or coconut oil, that would slow absorption of any kind of oats, and thus result in a lesser blood sugar spike. The truth is that “it depends“ is the answer here. We don’t have enough information about exactly how this study was conducted. In limited circumstances, you are correct. However, based upon what American consumers typically have (which can be pretty fairly judged by looking at how much shelf space is taken up by the different types of oats in a grocery store), you would likely not be correct. That is part of the reason why I tend to be skeptical of articles that summarize studies, because they tend to go for the easy headline, and the average person doesn’t know enough about nutrition to be able to fairly evaluate those results. Like anything else, some studies are well done, and others are less so.