It sounds like it isn’t even a study. It’s some kind of medical records system that popped a flag bc a certain threshold of people in a certain group had a certain medical issue.

Every 40 seconds, someone in the United States has a stroke. Every 3.5 minutes, someone dies of stroke. Every year, more than 795,000 people in the United States have a stroke. About 610,000 of these are first or new strokes. About 185,000 strokes—nearly 1 in 4—are in people who have had a previous stroke. About 87% of all strokes are ischemic strokes, in which blood flow to the brain is blocked.

Some quick maths tells me that 40000 Americans would normally have a stroke in that period. This won’t become a stroke epidemic. A 0.024% risk of stroke in the vaccinated elderly population sounds like better odds than catching covid unvaccinated