We see that either the detonation of the Genesis device or the associate explosion of the starship removes the nebula in an eyeblink. We then see immobile smoke rings being generated at regular distances outside the explosion, like surf atop otherwise invisible standing waves. Then the camera cuts to bridge action, and then back to a viewscreen image of the planet in turmoil.
There is no way to tell whether the planet in turmoil was at the center of the explosion or not. There is no trace of smoke rings in the turmoil image, least of all them "shrinking". Nor is there any indication that the planet is "forming". It's merely glowing a fiery orange, surrounded by amber clouds.