From that link: "Someone noticed the connection between the five cities Morthal, Whiterun, Winterhold, Dawnstar, and Windhelm, and realized they formed a Pentagon." Except they dont. A pentagon has equidistant points and these cities are not. At most you can say these cities form a 5 sided shape, but then they would have to, wouldnt they?
The surest sign that an argument against something is floundering is when weak points or non points are being offered up, nitpicking for example. A pentagon is defined as a shape with five sides, period. A five point star with internal segments is a pentagon, but has intersecting sides and is not a "simple" polygon. A square looking shape with a triangular wedge from two corners into the middle of the square cut out is a pentagon, but not a convex one. What you speak of is an equiangular and equilateral pentagon, or regular pentagon, and no, it is not necessary for the five city's locations to be that to form a pentagon, although in real world lore/mythology/magic traditions, the version used in rituals often is.
As I said, I find the leaps that led to the idea a bit of a stretch, but none of them are beyond logic or common sense as the clear parody video made out. Was merely pointing out how there is a real or serious effort to link these things up that led to the conclusion. It is far from time to march out the red herrings, weak last ditch points, or nitpick at details as though all reason for real doubt has been lost. I think we can safely poke at the difficulties in translating the runes, and the further fact that not all of them are clear in the first place. In fact, the noticing that those five cities form a pentagon with a dragon mound at midpoint on the connecting lines is really almost an unrelated issue and could have a real basis in planned architecture from way back in the days when dragons ruled. As has been stated, nowhere in previous lore has any summoning required a ritual involving such.
However, if you read their attempts to translate, it is those that lead to the tie in with the eight towers and the prophecy spoken of in that first book you find, the book of the dragonborn. It was almost a parallel issue that there happens to be a geometic correlation in the cities. Bear in mind that the likeliest explanation of larger scale quest idea that never made it into the final game leaving artifacts could be true and that the people digging into old norse runes may have also put together what that would have been. Perfectly possible and non exclusive explanations.
But my main point was simpler than all that. It was just this: the possibility of unmaking the last of the eight towers that anchor creation is a "real" thing in the lore of the series universe whether some runes on the lid of bug jars were an actual intentional clue to it or just seeing patterns in the cloud. A truth is uncovered, so accidentally or intentionally, those bugs served a purpose.