No, it does not. It is just an explanation of what happens when you use the materia and does not tell that it has happened before. I know the picture, but thanks anyway. They did not know how to summon it. Once the knowledge is inside the lifestream and you are able to read it without your mind breaking you can summon the natural power without materia. And Sephiroth has absorbed a great amount of the lifestream while he travelled through the lifestream. And Meteor does not take a great amount of the lifestream's energy to summon it, the forme of the magic itself is drained lifestream like the Ultimania says but Sephiroth's meteor was no Meteor formed by the planet, it was a Meteor which already existed. Sephiroth himself says that the materia is used to call a Meteor from space. There is no reason to waste the planet's energy which he wants to absorb. Her only needed his extremly strong mind, the strongest mind of all like we all know and like it was mentioned in an interview and like it is mentioned in the Ultimania Omega, and the knowledge within the materia.
The Cetra did not create it because the Cetra didn't create any materia. The planet itself always creates materia. And technically every offensive spell can harm the planet so it is no question why it would do that, not to forget that the question is irrelevant anyways since there is no reason for it but to have a counterpart of Holy for the Story. The Cetra of course sealed the materia in forme of the Temple. But nothing else.
EDIT@Wolf Kanno: I already know your ability not to accept the facts, so please stop replying. You can think what you want. I don't try to convince you anymore. What you think will not change the facts. And no, not everything in Final Fantasy VII is well-thought. I do know that. And the Ultimania Omega does contain the truth as it is in Final Fantasy VII except just one mistake.