The book Morman Doctrine wasn't pubished by Elder McConkie while he was an Apostle but rather while he was a General Authority.
More information can be found under a wiki document regarding the book found here
There are other books that have been printed with the full approval and authorization of the first presidency other than the four standard works listed above.
While I have not heard of the book you mention, should you obtain a copy, read the preface. If it is authorized and approved by the first presidency then it will have a statement from them indicating so. Otherwise you might see something like this:
The Miracle of Forgiveness
By Spencer C. Kimball
While President of the Church
"I accept full responsibility for the contents of this book. Specifically, the Church and its leaders are totally absolved from the responsibility for any error which it may be found to contain".
Is it doctrinal? It was spoken by the Prophet while in his office.
I say yes.