grammar - Is there anything wrong with the usage of "the more exciting" this sentence?

You don't need to use one as not using it is idiomatic. The definite article the is used before a comparative when you compare two things or people and usually of the two is used or omitted at the end.

Nearly all of the editors of the magazine agree that of the two
articles to be published, Fujimura's is the more exciting (of the two).

Of the two is omitted because it was used before.

Other examples:

This book is the more interesting of the two.
Who is taller, Tom or
Dick? Tom is the taller of the two.

You don't use one in the above examples.