No this is not just a coronal cavity, this is a sphere clearly connected to the suns surface, and the cord connecting it remains at the sphere when it releases, indicating it is a solid object with a physical "string" connected to it. The "cord" here is not a sun flare or anything like that neither, since they do not behave in this fashion. Nor do the coronal cavities stay connected to the sun for several days as in this video, just to release and let go.

Coronal cavities are type of "bubbles" in the suns atmosphere, or pockets of gas.

Btw, with your definition, could not the coronal cavities actually BE what causes planets to be born, with the beginning dust and matter within it that eventually forms the planet?