The wiki needs the context that universe destruction involves space-time destruction, not just physical aspects.
Regarding the true dragon's case, the entire case suggests the world in context includes a parallel universe and timeline in the section where the world's destruction statement was made. Hence, I think space-time destruction could be included in the universe's destruction, so the feat would be Low 2-C;
The entire text regarding the true dragon's case should have been posted because it gives more
evidence.
Overtime destruction would be irrelevant, if the universe is agreed upon as Low 2-C, according to
Ultima's explaination here based on math.
So, I think Low 2-C seems alright based on true dragon scaling.