Not a health professional here, but this does make sense to me. Another possible confounder I see in the case of Sweden is a stress level difference. If what I've read is correct, Sweden has been very light on the lockdown spectrum—especially if we look at lockdowns from a relative perspective, what is normal, everyday life to the average Swede would likely feel very restrictive to the average Brit and definitely to the average American.

Since it is known that the mRna vaccines have side effects that appear to most commonly affect the heart, it seems like a no-brainer that if you combine that with elevated stress levels due to lockdown/fear-mongering, you would see an increased rate of excess mortality in places where the societal stress is higher.