If somebody just came up with this theory now, no. However, there is evidence, that the Merovingian line believed they were the descendents of Mary Magdalene and Christ. As wrong as they most likely were, it is a historical fact, and it is interesting.
I find the history of the Rosenberg's interesting, even though they were on the wrong side of history. I am going to withold judgement on this one, until the report airs.
If it is done respectfully, and balanced in the sense that it shows how much of a minority this position is, while at the same time, dealing with the history of those who believed this to be true, it could be compelling viewing. The Knights Templar were most likely kooks. It doesn't make them uninteresting though. There was alot of strange stuff being believed. I find the history of the late middle ages to be intriguing. You had witches, alchemists, and secret societies. What's boring there? You can study this, without taking it to be Gospel truth.